DEVELOPING A FRAMEWORK FOR SUSTAINABLE ... Ismail...Science and Engineering Faculty Queensland University of Technology 2018 Developing A Framework for Sustainable Industrialised Building

DEVELOPING A FRAMEWORK FOR

SUSTAINABLE INDUSTRIALISED

BUILDING SYSTEMS FOR

INFRASTRUCTURE PROJECTS IN

MALAYSIA

Sushilawati Ismail

B.Eng (Hons) Civil Engineering, MSc. Civil Eng (Construction Management)

Submitted in fulfilment of the requirements for the degree of

Doctor of Philosophy

School of Civil Engineering and Built Environment

Science and Engineering Faculty

Queensland University of Technology

2018

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia i

Keywords

Industrialised Building System (IBS), Infrastructure, Redevelopment, Sustainable

Infrastructure

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia ii

Abstract

Sustainability has become an important aspect of the construction industry. The

Malaysian Government launched the Construction Industry Master Plan 2006-2015

(CIMP) initiative to uphold sustainable construction in Malaysia (CIDB, 2007). One

of the strategic thrusts under CIMP emphasises the application of an industrialised

building system (IBS) as an innovative construction method that responds well to

green construction and sustainability. Following the successful implementation of the

CIMP, the Construction Industry Transformation Programme 2016-2020 (CITP) was

initiated by the Malaysian Government to drive sustainable construction excellence in

the industry (CIDB, 2015). Recognising the importance of infrastructure to a nation’s

growth towards sustainable development, the CITP aims to make local infrastructure

more resilient and sustainable, to align with the sustainability goal of the Eleventh

Malaysia Plan (EPU, 2015a).

Infrastructure is expected to provide long-term service to satisfy public need into

the future. After decades of service, poor condition and under-performance of existing

infrastructure requires redevelopment efforts to prolong and revive the infrastructure’s

life and performance. The fact that infrastructure development requires large resources

and massive investment calls for sustainable practice in infrastructure project delivery

throughout the project life cycle. IBS was emphasised by the Construction Industry

Development Board (CIDB) Malaysia as one of the solutions for sustainable

construction. Furthermore, IBS has been identified as an option to promote flexibility

and interchangeability in accommodating the different demands for built infrastructure

redevelopment. Given this, it is essential for the industry to enhance sustainable IBS

in the construction industry, which motivated this research to further explore the

application of IBS in infrastructure projects and its potential in facilitating

infrastructure redevelopment.

This research aimed to develop a framework to promote sustainable IBS

application in coping with the demands of built infrastructure redevelopment in

Malaysia, with four main objectives: i) to explore the current status of IBS application

in infrastructure development, ii) to identify the contribution of IBS application to

infrastructure sustainability, iii) to examine the potential of IBS application in

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia iii

facilitating the redevelopment of built infrastructure, and iv) to develop a framework

of sustainable IBS application for infrastructure projects. To achieve these objectives,

a preliminary conceptual framework was initially developed based on a systematic

literature review. Semi-structured interviews involving 20 participants were

undertaken to gain insightful opinions from construction practitioners to determine

their perception towards IBS application in the construction industry; the applicability

of IBS, particularly in infrastructure projects; the strategies for IBS delivery; and the

sustainable potential of its application. A two-round Delphi study involved 13

experienced and knowledgeable panellists to further identify, verify, and prioritise the

factors developed from the literature review and interview findings. The results were

then synthesised and triangulated to demonstrate a holistic insight.

This research has produced a number of findings. Firstly, four categories of

important elements were identified to be considered for implementing IBS in

infrastructure projects: design requirements, policy, project characteristics, and

industrial readiness. Secondly, integration of IBS attributes and performance were

found to correspond well with the three pillars of sustainability principles: economic,

social, and environment. Further, it was found that optimisation of IBS application

through its capacity of changeability and adaptability can facilitate redevelopment

works. These findings contributed to the development of a framework for sustainable

IBS application for an infrastructure project that incorporates future redevelopment

consideration to enhance the sustainability of infrastructure projects.

This framework provides project stakeholders with a roadmap from a holistic

perspective to assist with making optimal decisions relating to IBS application in

infrastructure projects. Strategies for enhancing the effectiveness of IBS applications

are provided, highlighting the consideration of post-construction phase requirements.

Further research is recommended to provide a comprehensive guideline for IBS

application throughout the lifecycle of an infrastructure project phase. It is therefore

recommended that future studies incorporate the framework developed within this

research.

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia iv

Table of Contents

Keywords .................................................................................................................................. i

Abstract .................................................................................................................................... ii

Table of Contents .................................................................................................................... iv

List of Figures ........................................................................................................................ vii

List of Tables ........................................................................................................................... ix

List of Abbreviations ............................................................................................................... xi

Glossary .................................................................................................................................. xii

Statement of Original Authorship ......................................................................................... xiii

Acknowledgements ............................................................................................................... xiv

Chapter 1: Introduction ...................................................................................... 1

1.1 Overview ........................................................................................................................ 1

1.2 Background of the Research Problem ............................................................................ 1

1.3 Research Questions ........................................................................................................ 8

1.4 Research Aim and Objectives ...................................................................................... 10

1.5 Significance of the Study ............................................................................................. 11

1.6 Scope and Limitations .................................................................................................. 13

1.7 Overview of Research Methodology ........................................................................... 14

1.8 Thesis Outline .............................................................................................................. 16

1.9 Chapter Summary ........................................................................................................ 18

Chapter 2: Literature Review ........................................................................... 19

2.1 Introduction .................................................................................................................. 19

2.2 Infrastructure and Sustainable Development ............................................................... 19 2.2.1 Overview ............................................................................................................ 19 2.2.2 Infrastructure in Context .................................................................................... 20 2.2.3 Sustainability of Infrastructure Development .................................................... 21 2.2.4 Life Cycle of Infrastructure Development ......................................................... 28 2.2.5 Sustainable Delivery of Infrastructure Project ................................................... 30

2.3 Industrialised Building System (IBS) .......................................................................... 39 2.3.1 Overview ............................................................................................................ 39 2.3.2 IBS Adoption in Malaysia ................................................................................. 40 2.3.3 IBS: Drivers and Limitations ............................................................................. 45 2.3.4 Sustainable IBS .................................................................................................. 46 2.3.5 Delivery Strategies of IBS Implementation ....................................................... 50

2.4 IBS Application in Infrastructure Projects ................................................................... 54 2.4.1 Overview ............................................................................................................ 54 2.4.2 Drivers and Challenges of IBS in Infrastructure Projects .................................. 57 2.4.3 IBS Innovation and Technology in Infrastructure Projects ............................... 59 2.4.4 IBS Research Agenda in Promoting Sustainable Infrastructure ........................ 61

2.5 Nurturing Sustainability through Infrastructure Redevelopment ................................. 63

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia v

2.5.1 Concept of Redevelopment ................................................................................ 63 2.5.2 Redevelopment Contribution towards Infrastructure Sustainability .................. 65

2.6 Conceptual Research Framework ................................................................................. 66

2.7 Summary ....................................................................................................................... 68

Chapter 3: Research Design and Methods ...................................................... 71

3.1 Introduction .................................................................................................................. 71

3.2 Research Philosophy ..................................................................................................... 71

3.3 Research Design and Planning ..................................................................................... 74 3.3.1 Qualitative Design .............................................................................................. 75 3.3.2 Research Process ................................................................................................ 78 3.3.3 Data Analysis ..................................................................................................... 82

3.4 Literature Review ......................................................................................................... 83

3.5 Interview ....................................................................................................................... 86 3.5.1 Identifying and Approaching Participants .......................................................... 87 3.5.2 Sending the Invitations and Setting the Appointments ...................................... 88 3.5.3 Conducting and Concluding the Interviews ....................................................... 89

3.6 Analising Qualitative Data ........................................................................................... 91

3.7 Delphi Study ................................................................................................................. 97 3.7.1 Overview ............................................................................................................ 97 3.7.2 Selection of Delphi Participants ....................................................................... 100 3.7.3 Procedures for the Delphi Study ....................................................................... 102 3.7.4 Conducting a Delphi Study .............................................................................. 107

3.8 Data Triangulation ...................................................................................................... 119

3.9 Research Rigour and Validity ..................................................................................... 120 3.9.1 Establishing Rigour in Qualitative Research .................................................... 120 3.9.2 Methodological Rigour in a Delphi Study ........................................................ 123

3.10 Ethical Issues .............................................................................................................. 125 3.10.1 Risk 125

3.11 Summary ..................................................................................................................... 126

Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects .......................................................................................... 127

4.1 Introduction ................................................................................................................ 127

4.2 Profile of Interviewees ................................................................................................ 127

4.3 Interview Results ........................................................................................................ 129 4.3.1 Perception of IBS Implementation in Infrastructure Projects. ......................... 129 4.3.2 Applicability of IBS Adoption in Infrastructure Projects ................................. 138 4.3.3 Strategies for IBS Implementation in Infrastructure Project Delivery ............. 142 4.3.4 Sustainability Potential of IBS in Infrastructure Projects ................................. 146

4.4 Summary ..................................................................................................................... 155

Chapter 5: Results of the Delphi Study .......................................................... 157

5.1 Introduction ................................................................................................................ 157

5.2 Profile of Delphi Panellists ......................................................................................... 158

5.3 Results and Findings of Delphi Study ........................................................................ 160 5.3.1 Exploration of IBS Application in Infrastructure Development ...................... 160

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia vi

5.3.2 Identification of IBS Contribution to Infrastructure Sustainability ................. 172 5.3.3 IBS Optimisation Strategies for Infrastructure Redevelopment ...................... 177

5.4 Reliability of the Delphi Results ................................................................................ 180

5.5 Summary .................................................................................................................... 181

Chapter 6: Discussion ...................................................................................... 183

6.1 Introduction ................................................................................................................ 183

6.2 IBS Application in Infrastructure Projects ................................................................. 183 6.2.1 Perception of IBS ............................................................................................. 183 6.2.2 Consideration Factors of IBS Implementation in Infrastructure Projects ........ 186 6.2.3 Drivers of IBS Adoption in Infrastructure Projects ......................................... 193 6.2.4 Challenges of IBS Application in Infrastructure Projects ................................ 198 6.2.5 Summary .......................................................................................................... 201

6.3 IBS Delivers Sustainable Infrastructure ..................................................................... 204 6.3.1 Environment .................................................................................................... 209 6.3.2 Social ............................................................................................................... 210 6.3.3 Economic ......................................................................................................... 212

6.4 Promoting IBS Application in Infrastructure Projects by Considering Future Redevelopment ..................................................................................................................... 213

6.5 IBS Strategies for Facilitating Future Redevelopment of Built Infrastructure .......... 218

6.6 Developed Sustainable IBS Application Framework for Infrastructure Project ........ 221

6.7 Summary .................................................................................................................... 225

Chapter 7: Conclusion ..................................................................................... 227

7.1 Introduction ................................................................................................................ 227

7.2 Review of Research Objectives and Development Processes .................................... 227

7.3 Key Findings .............................................................................................................. 228 7.3.1 Extant Literature .............................................................................................. 228 7.3.2 Research Question 1 ........................................................................................ 229 7.3.3 Research Question 2 ........................................................................................ 230 7.3.4 Research Question 3 ........................................................................................ 231 7.3.5 Research Question 4 ........................................................................................ 232

7.4 Research Contributions .............................................................................................. 233 7.4.1 Contributions to Academic Knowledge ........................................................... 233 7.4.2 Contributions to the Industry ........................................................................... 235

7.5 Limitations ................................................................................................................. 236

7.6 Recommendations for Future Research ..................................................................... 237

7.7 Concluding Remarks .................................................................................................. 239

Bibliography ........................................................................................................... 241

Appendices .............................................................................................................. 271

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia vii

List of Figures

Figure 1-1: Evolution and challenges of sustainable construction in a global context ............................................................................................................ 2

Figure 1-2: The influence of a built asset on the natural environment ........................ 3

Figure 1-3: IBS Thrust in the Construction Industry Master Plan ............................... 4

Figure 1-4: CITP initiatives towards sustainability ..................................................... 5

Figure 1-5: Guide for generating research questions ................................................. 10

Figure 2-1: Themes of Sustainable Development ...................................................... 22

Figure 2-2: Infrastructure systems assessment framework ........................................ 27

Figure 2-3: “Cradle-to-end” life cycle ....................................................................... 29

Figure 2-4: Life cycle of built environment assets..................................................... 30

Figure 2-5: The conceptual framework of sustainable infrastructure development processes. ................................................................................ 31

Figure 2-6: Temporal design versus physical building life cycle .............................. 36

Figure 2-7: Examples of hybrid IBS application in Malaysia .................................... 41

Figure 2-8: Types of IBS systems .............................................................................. 43

Figure 2-9: Products, subsystems and components of infrastructure identified as being suitable for standardisation and prefabrication .............................. 56

Figure 2-10: Number of relevant papers according to the combination of search themes .......................................................................................................... 61

Figure 2-11: Distribution of published papers from 2005 to 2016 ............................ 62

Figure 2-12: Conceptual research framework ............................................................ 67

Figure 3-1: The research “onion” ............................................................................... 72

Figure 3-2: Four research worldviews ....................................................................... 72

Figure 3-3: Diagram of Constructivist Inquiry .......................................................... 74

Figure 3-4: Interactive model of research design ....................................................... 76

Figure 3-5: Overall research approach ....................................................................... 78

Figure 3-6: Research process flowData Collection Method ...................................... 79

Figure 3-7: Systematic review process ...................................................................... 85

Figure 3-8: Forms of interviews ................................................................................. 86

Figure 3-9: General flow of the interview process ..................................................... 87

Figure 3-10: NVivo 11 interface ................................................................................ 93

Figure 3-11: Qualitative coding level ........................................................................ 94

Figure 3-12: Example of assembly of pattern coding ................................................ 96

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia viii

Figure 3-13: Multi-level coding ................................................................................. 97

Figure 3-14: The Delphi process ................................................................................ 98

Figure 3-15: The flow of Delphi study procedures. ................................................. 108

Figure 3-16: Items for Question 1 ............................................................................ 110




Figure 3-20: Items for Questions 5 and 6 ................................................................. 114


Figure 3-22: Triangulation of quantitative and qualitative data ............................... 119

Figure 4-1: Word cloud of 100 most frequent words explaining IBS ...................... 129

Figure 4-2: Compilation of IBS thoughts of interviewees. ...................................... 131

Figure 4-3: Example of infrastructure project referred by the interviewees ............ 138

Figure 4-4: Factors contributes to IBS application in infrastructure project ............ 141

Figure 5-1: The role of Delphi study in framework development process .............. 157

Figure 5-2: Composition of Delphi panellists by category ...................................... 158

Figure 5-3: Consideration factors of IBS for infrastructure projects by category. .. 164

Figure 5-4: Drivers of IBS for infrastructure project by category. .......................... 168

Figure 5-5: Challenges of IBS for infrastructure project by category. ..................... 171

Figure 6-1: Priority of consideration factors for IBS adoption ................................ 186

Figure 6-2: IBS consideration factors, drivers and challenges for infrastructure project appraisal ......................................................................................... 203

Figure 6-3: The sustainable IBS performance across sustainability pillars ............. 204

Figure 6-4: Framework for delivering sustainable IBS in infrastructure project ..... 223

Figure 6-5: IBS adoption strategies to facilitate future redevelopment ................... 224

Figure 7-1: Sustainable IBS towards infrastructure sustainability ........................... 232

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia ix

List of Tables

Table 2-1: Infrastructure sustainable indicator based on previous research .............. 24

Table 2-2: Design strategies by various researchers .................................................. 34

Table 2-3: Different sources of construction waste (Source: Gerth et al., 2013)....... 37

Table 2-4: IBS-related initiatives by the Malaysian Government ............................. 41

Table 3-1: Selection of research methods .................................................................. 75

Table 3-2: Qualitative data collection: Advantages and limitations (Adapted from Fellow & Liu, 2008) ............................................................................ 81

Table 3-3: Rules of thumb for the selection of the data collection method ............... 82

Table 3-4: Difference between systematic and traditional review (Perry & Hammond, 2002) ......................................................................................... 84

Table 3-5: Goals of qualitative research (Bernard & Ryan, 2010) ............................ 92

Table 3-6: Traditional survey versus Delphi study (Adopted from Okoli & Pawlowski, 2004) ......................................................................................... 99

Table 3-7: Consensus and stability measurement .................................................... 105

Table 3-8: Typical cut-off point according to the type of Likert scale (Habibi et al., 2014) .................................................................................................... 107

Table 3-9: List of questions in Delphi questionnaire ............................................... 109

Table 3-10: Decision criteria recognising the relevant item .................................... 118

Table 3-11: Potential risks ....................................................................................... 126

Table 4-1: Interviewees demographic information .................................................. 128

Table 4-2: Interpretation of IBS definition by the interviewees .............................. 130

Table 4-3: A summary of IBS advantages. .............................................................. 132

Table 4-4: A summary of challenges of IBS applications. ...................................... 135

Table 4-5: A summary of IBS delivery strategies mentioned by the interviewees ............................................................................................... 143

Table 5-1: Profiles of the Delphi panellists ............................................................. 159

Table 5-2: Rating results for the consideration factors for adopting IBS ................ 161

Table 5-3: Mean ratings for consideration factors by panellist subgroup ................ 163

Table 5-4: Rating results for the drivers of IBS application in infrastructure projects ....................................................................................................... 165

Table 5-5: Mean ratings for the drivers by panellist subgroup ................................ 167

Table 5-6: Rating results for the challenges of IBS application in infrastructure projects ....................................................................................................... 169

Table 5-7: Mean ratings for the challenges by panellist subgroup .......................... 170

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia x

Table 5-8: Rating results for the sustainability attributes of IBS application in infrastructure projects ................................................................................ 172

Table 5-9: Mean ratings for the sustainability attributes of IBS by panellist subgroup ..................................................................................................... 174

Table 5-10: Rating results for IBS adaptability criteria in facilitating infrastructure redevelopment ..................................................................... 175

Table 5-11: Mean ratings for the adaptability criteria by panellist subgroup .......... 175

Table 5-12: Rating results for IBS changeability criteria for infrastructure redevelopment ............................................................................................ 176

Table 5-13: Mean ratings for the changeability criteria by panellist subgroup ....... 176

Table 5-14: Rating results for IBS optimisation strategies for infrastructure redevelopment ............................................................................................ 177

Table 5-15: Mean ratings for the optimisation strategies by panellist subgroup ..... 179

Table 5-16: ICC value for each round of Delphi survey. ......................................... 181

Table 6-1: Cross-construct of sustainable IBS attributes. ........................................ 206

Table 7-1: Consideration factors for IBS application .............................................. 231

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia xi

List of Abbreviations

ASCE American Society of Civil Engineering

CIDB Construction Industry Development Board

CIMP Construction Industry Master Plan

CITP Construction Industry Transformation Plan

DfMA Design for Manufacture and Assembly

GoM Government of Malaysia

IBS Industrialised Building Systems

ICC Intra-class correlation coefficient

IQR Inter-quartile range

KL Kuala Lumpur

LCA Life cycle assessment

O&M Operational and maintenance

SMLsystem Small, medium and large system

SPSS Statistical Package for the Social Sciences

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia xii

Glossary

Industrialised Building Systems (IBS)

An innovative construction approach that uses the concept of mass-production of product industrialisation under a controlled environment and incorporates transportation and assembly techniques with structured planning and process integration. IBS classification includes; i) a precast concrete system, ii) formwork system, iii) framing system (steel/prefabricated timber), iv) block work system, v) modular system, and vi) hybrid system

Sustainable development Development that meets the needs of the present without compromising the ability of future generations to fulfil their own needs (Bruntland, 1987)

Infrastructure Referring to the physical and organisational structures and facilities required for the operation of society. This physical capital provides long-term commitment and provision of commerce or interaction of goods, services, or people through transportation, transmission, distribution, collection, or other such capabilities. The examples include airports, transport transit hubs, bridges, schools, stadiums, mosques, multistorey car-parks, hospitals, and so on.

Redevelopment Redevelopment has an emphasis on the post construction stage, which could assist in optimising the remaining life cycle of existing built assets to minimise structure demolition. It involves a re-life process that may involve activities such as reconstruction, revitalisation, refurbishment, renewal, replacement, expansion/extension, and so on.

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysiaxiii

Statement of Original Authorship

The work contained in this thesis has not been previously submitted to meet

requirements for an award at this or any other higher education institution. To the best

of my knowledge and belief, the thesis contains no material previously published or

written by another person except where due reference is made.

Signature: QUT Verified Signature

Date: _________________________ September 2018

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia xiv

Acknowledgements

First and foremost, I wish to thank God, Alhamdulillahi Rabbil A’lameen, for

all of His blessings and permission. He gave me the physical and mental strength to

endure all of the challenges and hardships along this journey, which only happened with

His permission.

I would like to express my deepest gratitude to my principal supervisor, Dr Carol

Hon for all her valuable advice and enthusiastic support. Thank you for never giving

up on me and always motivating me to keep going. I am also thankful to Associate

Professor Philip Crowther for his insights and continuous support throughout this

research. My thanks also to Professor Martin Skitmore for his willingness to become

my associate supervisor. I convey special thanks to my former principal supervisor,

Prof Jay Yang, who I began this journey with. His guidance and encouragement will

never be forgotten.

I am deeply grateful to my supportive husband for always helping me to believe

in myself. My sincere gratitude to my parents, siblings, in laws, and all of my extended

family members for their endless prayers. Dear B, Ayah, and Mak, this journey would

not have been this smooth without your blessings. Thank you for everything. I am

hugely indebted to all of my so-called family in Brisbane, Piah, Alia, Jihah, Akmal,

and all of my Malaysian friends in Brisbane for their love and sharing all of the

struggles of being away from our home countries.

I would like to express my deepest appreciation to everyone who participated in

this research and contributed their time and knowledge along this research process. I

acknowledge that only their wisdom and help made this research possible and

successful.

I would also like to acknowledge the financial and academic support I received

from the Universiti Tun Hussein Onn Malaysia (UTHM) and the Ministry of Higher

Education (MOHE), particularly for the SLAI Scholarship; and thank Queensland

University of Technology (QUT) for providing the necessary financial support for this

research.

Developing A Framework for Sustainable Industrialised Building Systems for Infrastructure Projects in Malaysia xv

My thanks also to professional editor, Kylie Morris, who provided copyediting

and proofreading services according to the university-endorsed guidelines and the

Australian Standards for editing research theses.

Finally, it is a pleasure to thank everyone who contributed in any way and made

the completion of this thesis possible.

Chapter 1: Introduction 1

Chapter 1: Introduction

1.1 OVERVIEW

This chapter describes the research background and research problem. It also

presents the research questions and objectives and delineates the scope and limitations

of the research. The final sections provide an outline of the thesis and the summary of

this chapter.

1.2 BACKGROUND OF THE RESEARCH PROBLEM

The construction industry generates impetus to the economy of a nation. In

Malaysia, the construction industry contributed 4% to the national gross domestic

product in 2015 and this is expected to increase up to 5.5% in 2020 (Construction

Industry Development Board (CIDB), 2015). The construction sector is expanding due

to high demand for modern and efficient infrastructure to support the development of

Malaysia to be an advanced nation. However, continuing demands have caused

damage to the industry reputation due to detrimental impacts of climate change,

resource depletion, and energy constraint. The development of the construction

industry is therefore critical to sustaining economic growth, preserving ecological

balance, and enriching the general prosperity of a nation.

Confronted with the issues of environmental degradation and an energy crisis,

sustainability has become a manifested paradigm to control human activities in every

field. Sustainable development was originally defined as “development that meets the

needs of the present without compromising the ability of future generations to fulfil

their own needs” (Bruntland, 1987). The concept of sustainability comprises of three

main pillars: economic, social, and environmental. This concept embraces a more

inclusive society in which the benefits of increased economic prosperity are widely

shared, with ecological-friendly and more efficient consumption of natural resources.

It is apparent that this concept complements the global vision on sustainable

development.

Sustainability has become an important consideration in the construction

industry in conjunction with promoting sustainable development and sustainable

2 Chapter 1: Introduction

living. Sustainable construction is generally based on healthy built-environment

concepts, which are concerned with resource efficiency and a balanced ecology life

cycle (Bari, Abdullah, Yusuff, Ismail, & Jaapar, 2012). Fundamentally, construction

projects used to aim for quality, time, and cost efficiency. However, challenges such

as resource depletion, devastation of nature and biodiversity, and harmful emissions

expand sustainable construction to a larger context. Figure 1-1 illustrates the evolution

of the sustainable construction concept in a global context. When moving towards

sustainable construction, the goals should interact with the three pillars of

sustainability: economy, social, and environment. Correspondingly, the sustainable

construction model by Kibert (2008) incorporated time and resource dimensions with

the seven main principles of sustainable construction: (i) “reduce”’ (by reducing

resources consumption), (ii) “reuse” (by reusing resources), (iii) “recycle” (by using

recyclable resources), (iv) “nature” (by protecting nature), (v) “toxics” (by eliminating

toxic resources), (vi) “economics” (by applying life-cycle costings), and (vii) by

focusing on “quality”. The construction industry faces challenges to accomplish

sustainable construction in a global context (Ahuja, 2013).

Figure 1-1: Evolution and challenges of sustainable construction in a global context

(Adapted from Ahuja, 2013)

The construction industry has recently begun to consider the sustainability

concept in most construction phases, including the construction process, operation,

maintenance, and demolition of built facilities (Pearce, Ahn, & HanmiGlobal,


2012).Beyond this, the life cycle of construction projects should cover the pre-

construction phases: project planning and design. Early consideration towards

incorporating sustainable practices and embedding them into project documentation

and contracts at the planning stage is important to guide policymakers, stakeholders,

and practitioners to deliver a project sustainably (Binney, 2014; Yates, 2014). Various

concepts for sustainable design strategies, such as a holistic-sustainable design

(Swamy, 2001), multi-generation life-cycles of eco-design (Go, Wahab, &

Hishamuddin, 2015), design for disassembly (Crowther, 2005), and industrial flexible

and demountable building systems (Richard, 2006) specifically focus on resource

optimisation while signifying ecological concerns. Implementation of lean

construction procedures and adoption of a modern construction approach will improve

construction productivity, enhance material utilisation, and reduce safety risks and

economic uncertainties (Ahuja, 2013; Nahmens & Ikuma, 2012). Furthermore, the

deconstruction and recovery initiative could assist in optimising the remaining life

cycle of existing built assets in contrast to generating waste from demolition activities

(A. Shah & Kumar, 2005; Watson, Mitchell, & Jones, 2004) . As shown in Figure 1-2,

the flow of materials, energy, and waste into or out of a built facility throughout the

construction project life cycle generates the ultimate impact on the natural

environment.

Figure 1-2: The influence of a built asset on the natural environment

(Adapted from Pearce et al., 2012)


To transform the Malaysian construction industry to a higher level of

productivity and performance, the Government of Malaysia (GoM) developed the

Construction Industry Master Plan 2006-2015 (CIMP) initiative to uphold sustainable

construction in Malaysia (CIDB, 2015). The vision of CIMP is that of a progressive

construction sector that relies on sustainable development. Innovation has been

identified as one of seven strategic thrusts under CIMP. Mentioned under Strategic

Thrust 5: Innovate through research and development and adopt new construction

methods, the importance of an industrialised building system (IBS) was emphasised

specifically for greater success of CIMP, as depicted in Figure 1-3. IBS was introduced

by the Malaysian Construction Industry Development Board (CIDB, 2003) as a

potential solution to respond to green construction and sustainability (Abd Hamid et

al., 2004). Figure 1-3 summarises action plans and programmes to promote innovation

through the execution of a IBS roadmap.

Figure 1-3: IBS Thrust in the Construction Industry Master Plan

(Adapted from CIDB, 2010)


Following the successful implementation of the first CIMP master plan, CIDB

and the industry are currently on track for the adoption of the extension to the CIMP,

the Construction Industry Transformation Programme (CITP) (CIDB, 2015). The

GoM officially launched the CITP as a strategic enabler to transform the Malaysian

construction industry to be more quality-conscious, ecologically responsible,

productive, and globally competitive. CITP acknowledges the importance of

sustainability to Malaysia’s nation development, thus several initiatives have been

established to drive sustainable construction excellence in the industry (CIDB, 2015),

as shown in Figure 1-4. The first initiative envisions the development and

implementation of a sustainable infrastructure rating tool that will be customised for

the Malaysian context (CIDB, 2015). This was expected to raise awareness and

provide accessibility to sustainability practices across the local industry. Furthermore,

research partnerships and joint industry advisory projects have been drafted by the

GoM to drive innovation in sustainable construction (CIDB, 2015).

Figure 1-4: CITP initiatives towards sustainability

(Adapted from CIDB, 2015)


In recent years, much of the innovation developed regarding materials,

techniques, and technologies in the construction industry has centred on sustainability

practices. Effective use of innovation can provide a competitive advantage for

construction stakeholders to support improvement in process, products, and systems

(Blayse & Manley, 2004). For this reason, the Malaysian Government encourages the

transition from conventional construction methods to the implementation of IBS in

construction projects.

The introduction of IBS in Malaysia has made a strong impact on the local

construction industry. The IBS concept has competitive advantages in promoting

sustainable construction, even though it has yet to attain the level of technology

adopted by developed countries (Hamid & Kamar, 2012; Kamaruddin, Mohammad,

Mahbub, & Ahmad, 2013). IBS is an innovative construction system that represents a

specialised construction method that adopts prefabricated or precast components

through off-site construction or modularisation. IBS is regarded as a sound approach

for minimising the whole-life-cycle cost (Y. Chen, Okudan, & Riley, 2010a), uplifting

productivity and quality (Boyd, Khalfan, & Maqsood, 2013; Jaillon & Poon, 2008),

and enhancing environmental preservation (Bari, Abdullah, Yusuff, Ismail, & Jaapar,

2012; Kamarul Anuar Mohamad Kamar, Abd. Hamid, Ghani, Egbu, & Arif, 2011;

Lachimpadi, Pereira, Taha, & Mokhtar, 2012; Yunus & Yang, 2014). It also provides

for the efficient use of resources through minimisation of manpower, construction

processes, and material wastage (Burgan & Sansom, 2006; CIDB, 2003, 2010;

Crowther, 2005; Jaillon & Poon, 2008; Olmati, Trasborg, Naito, & Bontempi, 2015;

Tam, Tam, Zeng, & Ng, 2007).

Regardless of the potential of IBS in promoting sustainable construction, the

efficiency of its application in all kinds of construction projects remains unclear.

Although research into IBS is growing year by year, most research only discusses IBS

implementation in general (Blismas & Wakefield, 2009; Gibb & Isack, 2003; Nadim

& Goulding, 2010) or focuses on multi-storey buildings (Arif, Egbu, Mohammed, &

Egbu, 2010; Boyd et al., 2013; Jaillon & Poon, 2009; J. H. Meiling, Sandberg, &

Johnsson, 2014; W. Pan, Dainty, & Gibb, 2012; Pons & Wadel, 2011). Despite the

widespread application and success of IBS in sustainable multi-storey building

projects, there is scant research about the application of IBS in other infrastructure


projects for sustainability. Without this awareness, the contributions of IBS

applications in infrastructure projects towards sustainability cannot be fully optimised.

Many studies (Binney, 2014; Boyle et al., 2010; Brown, 2012; Fischer &

Amekudzi, 2011; Lenferink, Tillema, & Arts, 2013; Lim & Yang, 2007; Morrissey,

Iyer-Raniga, McLaughlin, & Mills, 2012; Pollalis, 2012; Sarte, 2010; Willetts,

Burdon, Glass, & Frost, 2010) have highlighted various strategies and methods to

reinforce sustainable infrastructure development. Physical infrastructures in particular,

which provide long-term service yet require a decade or more to construct, deserve

due attention. Physical infrastructures require commitment for improvement for long

gestation periods. This is crucial, because the failure to consider the long-term view in

project planning, as well as maintenance projection, results in a struggle for sustaining

existing infrastructure (Ascher, 2010). The demand for infrastructure development is

parallel with economic and community growth. It requires a holistic approach to

nurture sustainability practices in the infrastructure project at every stage. It is

therefore essential to minimise energy consumption and control the environmental

impacts of the proposed project while achieving optimisation of an owners’

investment. For this reason, the successful delivery of sustainable infrastructure

projects has always been at the centre of attention in infrastructure development.

Rapid population growth in developing countries such as Malaysia has created

increasing demand for civil engineering and infrastructure projects year by year. The

relatively poor status of existing infrastructures in many countries clearly highlights

the need to incorporate maintainability and sustainability aspects into the planning and

design processes (Kumaraswamy, 2011). Appropriate design and well-maintenance

could maximise the infrastructure’s service life, thus enhancing resource conservation

(United Nations ESCAP, 2006), as the lack of post-construction phase consideration

in project planning could ruin sustainable infrastructure performance. It is therefore

necessary to emphasise operation and maintenance processes, while at the same time

integrating the redevelopment potential for prolonged infrastructure service life

(Bokalders & Block, 2012). Lessons can be learned from other places, such as Hong

Kong, where new infrastructure requires a new-built consideration shift towards

maintenance, redevelopment, and rehabilitation potential.

IBS can be seen as an option to promote flexibility and interchangeability

through an open building system. This system allows the building components or sub-


systems to be easily replaceable (CIDB, 2010). Simultaneously, the flexibility

advantages could accommodate the different demands to facilitate the evolving needs

of the end users (Ye, Hassan, Carter, & Kemp, 2009). As infrastructures are expected

to cope with high maintenance and demand expansion over time, redevelopment

activities such as renewal, revitalisation, upgrades, renovation, and refurbishment may

be required to optimise the life of the built infrastructures. Moreover, such activities

could enhance resource conservation by avoiding demolition or the excessive resource

consumption of constructing new infrastructure, leading to the need to explore the

potential of IBS in facilitating the redevelopment of built infrastructures.

The above scenarios demonstrate the need to establish a decision support

guideline that optimises the potential of the IBS application to promote infrastructure

sustainability. There has been a lack of micro-level decision making in the built

environment, particularly in relation to infrastructure projects (Love, Edwards,

Watson, & Davis, 2010). Thus, it is essential to examine this specific issue to improve

project delivery effectively.

1.3 RESEARCH QUESTIONS

This research aims to develop a framework of sustainable IBS for infrastructure

projects in Malaysia using the concept of building sustainability as the foundation to

address sustainable IBS application and to highlight the potential of IBS in

infrastructure redevelopment towards infrastructure sustainability. There are three

main research subjects in this study: IBS, infrastructure, and sustainability. Based on

the interrelation between these subjects (shown in Figure 1-5), this research addresses

the following research questions:

Q1. What are the perceptions of the construction industry with regard to IBS

application in infrastructure projects?

Essentially, there is lack of a common understanding about “IBS” amongst the

multiple stakeholders. As limited existing research has specifically investigated IBS

implementation in infrastructure projects, identifying and exploring the awareness,

various understanding, and perceptions of these stakeholders could help to promote

more integrated thinking and a consistent approach to optimising IBS implementation

strategies at every project level.


Q2. What are the important elements or factors for infrastructure projects to apply or

adopt IBS?

There are various reasons as to why the application of IBS is not well-used in

infrastructure projects. However, very limited research has been conducted on this

topic. IBS seems challenging for infrastructure projects, despite having been

practically applied in many infrastructure projects (Larsson, Eriksson, Olofsson, &

Simonsson, 2014). These arguments can be determined by recognising the common

characteristics of infrastructure projects that have chosen to apply this construction

system. Moreover, by examining the numerous elements and factors of an

infrastructure project, the extent of IBS applicability and capabilities can be

determined.

Q3. How can IBS application contribute to infrastructure sustainability?

The complexity and unique nature of infrastructure projects often causes

challenges in the pursuit of sustainability goals throughout the project life cycle. These

challenges must be acknowledged in order for measures to be taken to address them.

IBS is a promising solution for promoting sustainable construction yet delivering

sustainable projects. It is therefore essential to fundamentally understand and

acknowledge the potential of IBS in contributing towards infrastructure sustainability.

Q4. How can redevelopment potential promote IBS application in infrastructure

projects?

Sustainability should be a desired outcome for every project stakeholder during

the decision-making process. Every phase of infrastructure development should be

guided by the principle of sustainable development (Lim & Yang, 2007). According

to the literature review, the post-construction phase in an infrastructure project life-

cycle is critical, as infrastructure provides long periods of operation. This has led to

serious concern into examining this phase to maintain the life of infrastructure.

Existing structures should have the capability to regenerate, rehabilitate, retrofit,

repair, and so on, in order to optimise resource consumption by avoiding demolition

and contemplating the construction of new structures. These activities, termed

“redevelopment”, could elevate the remaining life cycle of existing built

infrastructures. Thus, the capability of IBS to accommodate future redevelopment

needs to be determined before discovering how IBS could support its necessity.


Accordingly, decision making in regards to IBS application should incorporate and

consider redevelopment needs beforehand. It is therefore necessary to recognise and

discover the practical strategies and action plans related to IBS delivery, in order to

determine the efficiency and effectiveness of IBS deliverables to facilitate the

redevelopment of built infrastructure.

Figure 1-5: Guide for generating research questions

1.4 RESEARCH AIM AND OBJECTIVES

This research aims to develop a framework to promote sustainable IBS

applications that will cope with the demands of built infrastructure redevelopment in

Malaysia. The following research objectives were therefore developed:

Objective 1: Explore the current status of IBS application in infrastructure

development by:

Understanding the concept of IBS implementation in construction industry.

Reviewing the existing research within the IBS-sustainability-infrastructure

domain systematically and critically.


Exploring the perception of construction stakeholders with regards to IBS

implementation in infrastructure projects.

Recognising the drivers and challenges of IBS in infrastructure projects.

Identifying the applicability criteria and infrastructure project

characteristics to opt for IBS adoption.

Objective 2: Identify IBS application contribution to infrastructure sustainability by:

Identifying the sustainability of IBS implementation throughout the

construction project life-cycle.

Identifying the IBS attributes required for delivering sustainable

infrastructure.

Objective 3: Examine the potential of IBS in facilitating the redevelopment of built

infrastructures by:

Understanding the context of redevelopment and its contribution towards

infrastructure sustainability.

Identifying the potential of IBS in facilitating infrastructure redevelopment.

Recognising the strategies for optimising the potential of IBS to facilitate


Objective 4: Develop a framework of sustainable IBS application in facilitating

redevelopment for infrastructure projects by:

Integrating redevelopment consideration to elevate infrastructure project

sustainability.

Compiling and proposing practical strategies for sustainable IBS

optimisation in infrastructure projects delivery.

1.5 SIGNIFICANCE OF THE STUDY

This research has been formulated to contribute to and align with the CITP, to

ensure continuity and consistency with the Eleventh Malaysia Plan 2016-2020 agenda,

particularly in pursuing green growth for sustainability and resilience. The CITP

(CIDB, 2015) focuses on the following four strategic thrusts:


Thrust 1: Quality, safety and professionalism

Thrust 2: Environmental sustainability

Thrust 3: Productivity

Thrust 4: Internationalisation

This research is expected to directly contribute towards achieving the projected

outcome for Thrust 2, to classify “Malaysia’s sustainable infrastructure: A model for

the emerging world” (CIDB, 2015). This thrust is aligned to the sustainability goal of

the Eleventh Malaysia Plan: “Pursuing green growth for sustainability and resilience”,

and overall attempts to make Malaysia’s infrastructure more resilient and sustainable

while aiding environmental protection and ensuring Malaysian living standards are not

compromised.

To address the above, the CITP (CIDB, 2015) puts forward five core initiatives:

E1: Drive innovation in sustainable construction

E2: Drive compliance to environmental sustainability ratings and requirements

E3: Focus on public projects to lead the charge on sustainable practices

E4: Facilitate industry adoption of sustainable practices

E5: Reduce irresponsible waste during construction

This research was inspired by this initiative in promoting sustainable

construction practices and to subsequently accelerate progression towards

environmentally sustainable development.

In order for Malaysia to become an advanced nation, there is recognition of an

increasing demand for infrastructure (CIDB, 2015). Infrastructure projects are

associated with long service life and subjected to continuous functioning and aging.

The high scale of energy usage for their construction and operation will have a

significant impact on the environment. This study, through exploration of a variety of

data, aims to show the applicability of a modern method of construction, IBS, in

preserving energy and material consumption, particularly in infrastructure projects.

The aspiration to achieve a healthy built environment and efficient use of resources is

critical towards attaining a more environmentally responsible and promising a more

sustainable construction industry.


To the best of the researcher’s knowledge, this research topic is relatively new

and lack of extensive study. The outcomes from this research aim to add to the existing

body of knowledge with respect to infrastructure project development and IBS

application towards sustainable development, which will be beneficial for adding

insight into the collective knowledge about issues pertaining to IBS implementation in

infrastructure projects. Moreover, it is anticipated that this research provides the

answers to the research questions and the empirical evidence regarding the existing

knowledge and literature.

Yet importantly, this research contributes to theoretical research on IBS potential

in facilitating redevelopment of built infrastructure. This research identifies that the

effectiveness of IBS could be enhanced by optimising its changeability and

adaptability principles. Accordingly, this research outlines the appropriate IBS

application strategies that need to be considered at the project planning level to

accommodate future changes to promote infrastructure sustainability. It provides a

new perspective and insights that broaden the studies in infrastructure project

development and IBS application for further research.

Finally, this research provides project decision-makers and practitioners with a

framework that is useful as a reference for identifying practical solutions by which to

reduce the environmental burden of an infrastructure project, especially in post-

construction stages. Project stakeholders should then be able to look beyond project

issues and begin to analyse the broader aspects of infrastructure sustainability.

Correspondingly, this research possibly creates awareness among construction

practitioners and extends opportunities to other researchers in the construction industry

to correspond to the CITP initiatives to accelerate the adoption of IBS, mechanisation

and modern practices in Malaysian construction industry.

1.6 SCOPE AND LIMITATIONS

This research is a combination of four research perspectives, namely

industrialised building systems (IBS) as the research object, sustainability as the

research focus, redevelopment as the research content, and infrastructure as the

research range. These delimitations are discussed below:


The attention of this research is directed to the context of Malaysian

construction industry; more specifically, it discusses the modern

construction method of IBS. The IBS terminology was originally embraced

by the CIDB of Malaysia. Therefore, the interpretation of this term is subject

to its implementation within local settings.

Primary research data were collected in Malaysia, and the research results

are interpreted within the Malaysian context. However, in order to obtain

more balanced viewpoints and references, secondary research data were

extracted globally. This includes lesson-learned from other developing and

developed countries with regards to their knowledge, technology, and

experiences in order to enrich the content and viewpoints.

Although this research is grounded in the broad context of infrastructure, it

primarily focuses on physical built infrastructures. The term “infrastructure”

in this research context comprises all physical elements of buildings and

civil structures, instead of the operational systems.

The respondents involved in this study had experience with infrastructure

projects and were exposed to the implementation of IBS. They represented

project developers, contractors, consultants, manufacturers and academic

researchers. The involvement of multiple project stakeholders in this study

provides holistic views and enriches the research outcomes.

Although the research findings of this study are based on the Malaysian context,

the knowledge gained through this study can be extrapolated to other developing

countries that may also attempt to advance their infrastructure sustainability.

1.7 OVERVIEW OF RESEARCH METHODOLOGY

This study is exploratory in nature. It combines qualitative and quantitative

methods using primary and secondary data. The qualitative approach is adopted

particularly to discover and deeply understand an area or phenomena where little is

known or the information is inadequate (thin, biased, partial) (Richards & Morse,

2002). In this case, the application of IBS in infrastructure projects is basically

practiced; however, there has been limited attention and it has not been extensively

examined in relation to how it contributes to the sustainability of infrastructure


development. The quantitative method was then employed to identify the influential

factors relating to IBS and sustainability concerns, as well as strategic strategies for

the development of a decision support guideline.

In order to accomplish the goal of this study, the overall research procedure was

designed to consist of three phases, as follows:

Phase 1: Literature studies

This phase involved a comprehensive review of interdisciplinary literature. The

review was carried out using journal articles, conference proceedings, dissertations,

books, government reports, and websites. Three main disciplines were explored,

including IBS, sustainability, and infrastructure development. The review integrated

and criticised various perspectives of scholarly works to formulate the preliminary

conceptual framework of this study. At the same time, the research gaps were

identified, with a particular focus on the perspective of redevelopment strategies in

infrastructure development.

Phase 2: Data collection and analysis

In the second phase of this study, semi-structured interviews and a Delphi study

were conducted for the main data collection. The interviews aimed to validate the

preliminary integration of the conceptual framework and also investigated perceptions

about and the current state of IBS application in infrastructure projects. A number of

findings extracted from the interviews also revealed the motivations and barriers of

IBS implementation. A Delphi study was then undertaken to obtain experts’ consensus

regarding the drivers, challenges, sustainable attributes, and strategies of infrastructure

projects in implementing IBS. During this phase, the qualitative and quantitative data

were processed and analysed using computer-assisted tools, such as NVivo and SPSS

to derive substantial and rich outcomes.

Phase 3: Development of framework and strategies.

The final phase was the development of the framework and strategies for

implementing sustainable IBS in infrastructure projects. Information and findings

obtained from prior phases were used to be incorporated with sustainability

consideration. Finally, a framework for the application of sustainable IBS was

developed to support future infrastructure redevelopment.


1.8 THESIS OUTLINE

This thesis consists of seven chapters. A summary of each chapter is provided

below:

Chapter 1: Introduction

This chapter comprises the introductory section, which presents the direction of

the research. It provides the research background relates to the sustainability issues in

the construction industry and the Malaysian construction initiative to encourage the

sustainable construction practices through IBS implementation. The identification of

the prominent issues led to the formulation of the research questions and objectives.

The chapter also provides a discussion of the overall research process and the research

subjects. This chapter aims to provide an overview of the entire research process.

Chapter 2: Literature Review

This chapter reviews the extant and current state of knowledge by addressing the

relevant background literature. It also presents the systematic review of scholarly

literature for the past ten years. The areas of review covered infrastructure

development; IBS; sustainable principle; and infrastructure sustainability, which

includes the redevelopment of built infrastructures. The systematic review also

illustrates the interrelationship within the research topic and provides the preliminary

conceptual framework. It also determines the research gap whereas the applicability

and adaptability of IBS in infrastructure projects remain to be unexplored.

Accordingly, this research niche underpins the need for this study to emphasise

infrastructure sustainability through the IBS implementation.

Chapter 3: Research Design and Methods

This chapters initially discusses the philosophy of the research conduct. It then

extensively discusses the research methodology and research design and includes the

selected research approach and data collection methods. The research is categorised as

constructivism paradigm which qualitatively designed. This study employed multi-

method data collection approaches includes literature review, semi-structured

interviews, and Delphi study. The justifications of each selected research approach are

then appropriately explained. Furthermore, this chapter also describes the data analysis

process to analyse the results of each research approach. Data triangulation method


also adopted to gain richer insight as well as provided the rigour and reliable outcome.

Accordingly, the ethical considerations of this research are then clarified.

Chapter 4: Understanding and Perception of IBS in Infrastructure Projects

This chapter initially describes the design of the semi-structured interviews

employed in this research that involved twenty selected participants from researchers

and industrial practitioners. The interviews validate the preliminary conceptual

framework that has been developed from the literature studies. This chapter also

provides a holistic view on local industry’s perceptions and understanding about IBS

application and infrastructure projects. Besides, it demonstrates the applicability of

IBS in infrastructure projects, the strategies of IBS delivery, and the sustainability

potential through IBS application in delivering sustainable infrastructure.

Chapter 5: Results of the Delphi study

This chapter describes the process of data collection and data analysis of the

Delphi study. The data and results from the two-round Delphi survey are presented. It

verifies the preliminary findings from interviews and literature. This chapter also

addresses the relevant and critical items relating to the consideration factors for IBS

application, the drivers and challenges of its implementation, the attributes that

contribute to infrastructure sustainability, and its potential to facilitate future

redevelopment. The reliability, stability, and accuracy of the Delphi results are also

appropriately explained.

Chapter 6: Discussion

This chapter provides a critical discussion of synthesised results and findings

from semi-structured interviews and two-round of Delphi study. The key consideration

factors and the sustainability contributions of IBS application for infrastructure

projects are discussed. The significance of redevelopment in promoting the

infrastructure sustainability are accordingly explained. The IBS application strategies

for facilitating future redevelopment are also consolidated. Correspondingly, the

overall results are represented as the “Framework for delivering sustainable IBS in

infrastructure projects” with the aim of assisting future construction practitioners with

their decision making.

Chapter 7: Conclusions


This chapter reviews the research objectives. It provides a summary of the

findings on the industry’s perception and important elements to be considered for IBS

application in infrastructure projects. It also summarises the contributions and

strategies of IBS towards infrastructure sustainability, particularly by considering

redevelopment potential. Besides, it also presents the contributions of this research to

the industry and academics on how to optimise IBS for sustainability with a list of

recommendations for future research opportunities

1.9 CHAPTER SUMMARY

This chapter provided the foundation of the research with regards to the

sustainable practice in construction projects with IBS implementation. The

interrelation between sustainability and IBS in infrastructure projects was highlighted

to explore the potential extent of this modern construction approach. To achieve the

research aim which to develop a framework to promote the sustainable IBS in

infrastructure projects, four main objectives were clearly established based on the

research questions. The significance and contributions were also clarified before the

research scope and delimitation were provided. The research methodology was then

briefly explained to ensure the objectives could be achieved. Finally, the flow of the

thesis was outlined.

Chapter 2: Literature Review 19

Chapter 2: Literature Review

2.1 INTRODUCTION

This chapter presents the current state of knowledge found in the literature. The

main objective of this literature review is to discover the depth and breadth of the

existing body of knowledge about infrastructure development, industrialised building

systems (IBS), and sustainability concerns. The literature also serves to provide

understanding about the relationship and dependency between IBS and infrastructure

in nurturing sustainable development. The redevelopment potential of built

infrastructure is also discussed to explain its contribution in supporting sustainable

development.

Based on an extensive literature review conducted on IBS, sustainability, and

infrastructure, an absence of studies integrating these three components in a

construction project delivery framework was identified. The identification of this gap

served as a guide to further extend the scope of this research into the development of

the research questions, establishment of the research objectives, and formulation of the

research design.

2.2 INFRASTRUCTURE AND SUSTAINABLE DEVELOPMENT

2.2.1 Overview

Infrastructure is generally defined as the basic physical

and organisational structures and facilities required for the operation of a society

or enterprise (Oxford Dictionary, 2015). Infrastructure projects are the backbone of a

nation’s economic and social growth. They support the provision of commerce or

interaction of goods, services, or people through transportation, transmission,

distribution, collection, or other such capabilities (Gibson, Bingham, & Stogner,

2010). In other words, it is the integration of socio-technical systems and the human-

natural environment in a continuous relationship. Thus, the development of an

infrastructure asset is not undertaken in isolation; rather it is always heavily dependent

on the integration between these factors.

20 Chapter 2: Literature Review

According to Martland (2012), infrastructure projects cover massive, complex,

longstanding investment in either water resources, buildings, transportation systems,

energy generation and distribution systems, communication, and public services. Thus,

comprehensive strategies are required to coordinate, plan, and improve their

productivity. Due to the unique nature of each infrastructure project, complex issues

arise in terms of uncertainties, risks, and the lasting impact on the environment, both

social and economic. For new technology integration in infrastructure projects,

consideration must therefore be given to holistic implications over the full coverage of

project life-cycle (Levitt, 2007).

Infrastructure plays a crucial role in a country’s development in terms of

economic, social, and ecological stability. In particular, long-term infrastructure

development projects are often large in project scope and financial scale (Ascher &

Krupp, 2010). As they require both high energy and resource consumption, there may

be a significant impact on the environment. Meanwhile, from the social aspect, to

provide long-term service, satisfactory maintenance and upgrades are necessary for

public comfort and satisfaction into the future. Ugwu and Haupt (2007) implied that

other priorities, such as capacity utilisation building and socio-cultural dimensions

should not be overlooked to sustain harmony and co-existence. Therefore, the adoption

of a sustainable approach is essential when developing infrastructure facilities.

2.2.2 Infrastructure in Context

The term infrastructure is generic, and it can be interpreted in many ways and

different contexts. Engineers Australia (2010) classified infrastructures into four main

categories: transport, water, telecommunications, and energy infrastructure. Salleh and

Okinono (2016) and Shen, Wu, and Zhang (2011) illustrated infrastructures into

various ranges of services from electricity, gas, telecommunications, water supply, and

sewerage as public utilities; with roads, dam, airports, community centres, and schools

classified as public works. The nature of infrastructures can also be broken into three

components: personal infrastructure, institutional infrastructure, and physical

infrastructure (Howes & Robinson, 2005). Personal and institutional infrastructures

refer to social and human capital, respectively, which relates to the provision of soft-

service facilities that are nurtured through investment in education, training, and other

social services. Physical infrastructure comprises of all of the physical structures and

constructed facilities required by society to stimulate socio-economic growth, and the


government has an important role in infrastructure project development. Heard,

Hendrickson and McMichael (2012) included buildings, roads, pipelines, bridges,

powerlines, canals, and waterways as examples of physical infrastructure.

Separate from this broad definition of infrastructure, Naidu (2008) described

infrastructure projects in Malaysia as the built stock of facilities that are provided to

the public and are comprised of transportation infrastructure (road, rail transport, and

ports), telecommunications, and electricity distribution. According to Business

Monitor International (2015), infrastructure projects include more than just building

projects. Meanwhile, Masrom, Rahim, Mohamed, Chen and Yunus (2015) classified

highways, railways, mass rapid transit, and airports as large infrastructure projects in

Malaysia. Typical infrastructure projects that were mentioned in the Eleventh

Malaysia Plan included airports, ports, roadways, and rail transport (Economic

Planning Unit (EPU), 2015b). In this research context, the term “infrastructure”

includes physical civil structures or built facilities that support the operation of society

and provide an interaction between goods, services, or people through transportation,

transmission, distribution, collection, or other such capabilities. Examples include

airports, transport transit hubs, bridges, schools, stadiums, mosques, multistorey car-

parks, and so on. This research focusses on such infrastructure projects because they

generally have unique design features, where the repeatability of components is limited

compared to typical multi-storey building projects. They are also subject to long-term

service and may require future changes to manage growing demand.

2.2.3 Sustainability of Infrastructure Development

Sustainability has become increasingly important in the development of built

environment. Driven by either government or industry initiatives, the core emphasis is

placed upon meeting the ecological and socio-economic aims of sustainable

development. In general, sustainable development is achieved when the needs of the

present are fulfilled without depriving the needs of future generations (Bruntland,

1987). The notion of sustainability that gauges the success of project development is

comprised of three broad components: social equity, economic prosperity, and

environmental protection. The theme set of sustainable development principles is

known as the “triple bottom line”, which places equality among all three of these

elements, as shown in Figure 2-1.


Figure 2-1: Themes of Sustainable Development

Infrastructure is not only a physical asset that contributes to economic growth, it

also has long-term social and environmental implications to create a holistic and

healthy environment (Lim, 2009). Because infrastructure development constitutes a

large resource and high energy consumption, as well as a huge investment,

investigation of each sustainability element is integral, as it affects sustainable

development universally. Therefore, to achieve sustainable infrastructure

development, it is essential to firstly understand the interrelationships between the

sustainability principles and infrastructure project characteristics.

There is a large body of literature about sustainable infrastructure. A

comprehensive set of sustainability indicators for an infrastructure project is essential

for sustainability performance measurement as a whole. Table 2-1 summarises

previous studies about the sustainability criteria of infrastructure development.

Fernández-Sánchez and Rodríguez-López (2010) and Willetts, Burdon, Glass and

Frost (2010) categorised sustainable indicators into three basic attributes of social,

economy, and environment. As shown in Table 2-1, Sahely, Kennedy and Adams

(2005) divided infrastructure sustainability criteria into four segments: (i) economic,

including expenditure and innovation investment; (ii) environmental, including

resource consumption and residual production; (iii) social, including accessibility,

acceptability, and health and safety; and (iv) engineering, which refers to performance.

According to Sahely et al. (2005), the most critical phase is the establishment of project

goals, system boundaries, and developing the sustainability attributes definition. This

was reinforced by Dasgupta and Tam (2005) who argued that defining justifiable


system boundaries could provide a clearer picture of an infrastructure system,

especially from an environmental point of view. Moreover, Dasgupta and Tam (2005)

measured infrastructure sustainability through four different categories: regulatory,

project-specific, environmental, and technical. Yet, these categories still ensure that

infrastructure project phases adhere to the same track of enhancing sustainability.

Table 2-1 also shows that previous studies have emphasised that environmental

issues, such as material waste and consumption, energy efficiency, and biodiversity

affect infrastructure sustainability (Fernández-Sánchez & Rodríguez-López, 2010;

Lim & Yang, 2007; Ugwu & Haupt, 2007; Willetts et al., 2010). The sustainability of

infrastructure projects goes beyond environmental conservation to provide a long-term

commitment to society (Willetts et al., 2010). As social aspects fall under the

overarching umbrella of the sustainability concept, Fischer and Amekudzi (2011)

incorporated community life quality and natural environment as a new paradigm of

infrastructure development. Social attributes, such as cultural sensitivity; community

perception and satisfaction; health, safety, and security; public attitude; and lifestyle

all contribute to quality of life. From a different perspective, Zeng et al. (2015) merged

economic, legal, ethical, and political responsibility to represent holistic social

sustainability. On the other hand, monetary-related criteria, such as the cost of capital,

operation, and maintenance; affordability; profitability; supply chain matters; and

project risks are categorised under economy elements, thereby also affecting



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urab

ilit

y •

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ctio

n pe

rfor

man

ce

NA

N

A

NA

2.

Ugw

u &

Hau

pt, (

2007

) an

d L

im &

Yan

g,

(200

7)

• Lan

d us

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ater

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ir

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se

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logy

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l im

pact

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aste

man

agem

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ost (

init

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life

cyc

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ttli

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cost

of

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men

t)

• C

ultu

ral h

erit

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cess

•

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lic

perc

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NA

• S

ite

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(2

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•

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alit

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and

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•

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lic

atti

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and

li

fest

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NA

N

A

NA

N

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4.

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nánd

ez-S

ánch

ez &

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odrí

guez

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ez,

(201

0)

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f al

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tors

•

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urit

y •

Pub

lic

util

ity

• S

ocia

l int

egra

tion

•

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pons

ibil

ity

NA

N

A

NA

N

A


No

Au

thor

s S

ust

ain

able

In

dic

ator

/Att

rib

ute

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iron

men

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con

omy

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ring

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tion

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lth

&

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ety

Pro

ject

M

anag

emen

t 5.

W

ille

tts,

Bur

don,

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ss,

& F

rost

(20

10)

• Res

ourc

e co

nsum

ptio

n • E

nerg

y ef

fici

ency

• W

aste

• C

lim

ate

chan

ge

• Wat

er c

onsu

mpt

ion

• Bio

dive

rsit

y an

d ha

bita

t • L

and

use

• Pro

cure

men

t • S

uppl

y ch

ain

• Pro

fita

bili

ty

• Com

peti

tive

ness

• G

row

th

• H

ealt

h an

d sa

fety

•

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mun

itie

s •

Ski

lls

• S

take

hold

er

sati

sfac

tion

•

Incl

usiv

enes

s

NA

N

A

NA

N

A

6.

Am

iril

, Naw

awi,

Tak

im, &

Lat

if (

2014

) • L

and

use

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er q

uali

ty

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qua

lity

• N

oise

qua

lity

• E

colo

gy a

nd

biod

iver

sity

• V

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l im

pact

• W

aste

man

agem

ent

• Ene

rgy

and

carb

on

emis

sion

s • P

ollu

tion

con

trol

s • E

rosi

on &

sed

imen

t co

ntro

l • F

lora

and

fau

na

• Pro

ject

ris

ks

• Lif

e cy

cle

cost

•

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tura

l her

itag

e •

Pub

lic

acce

ss

• P

ubli

c pe

rcep

tion

•

Hea

lth

and

safe

ty

• S

take

hold

er

rela

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ship

•

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r-m

odal

ity

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• M

ater

ial t

ype

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labi

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/ass

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• F

unct

iona

lity

, per

form

ance

of

phys

ical

ass

et

NA

• T

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of c

ontr

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men

t m

etho

d • P

roje

ct r

isks

7.

Zen

g, M

a, L

in, Z

eng,

&

Tam

, (20

15)

NA

N

A

• E

cono

mic

re

spon

sibi

lity

•

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al

resp

onsi

bili

ty

• E

thic

al

resp

onsi

bili

ty

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olit

ical

re

spon

sibi

lity

NA

R

egu

lato

ry

Pro

ject

Sp

ecif

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men

tal

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8.

Das

gupt

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Tam

, 200

5 • C

onfo

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a s

et o

f la

ws,

or

dina

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, reg

ulat

ions

and

sta

ndar

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roje

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impl

emen

tati

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pera

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s

• A

esth

etic

or

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itat

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s-re

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uman

hea

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and

poli

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logi

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ure,

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and

resp

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s

• M

ater

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nd e

nerg

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tens

ity

• M

ater

ial r

ecyc

led

inte

nsit

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id w

aste

gen

erat

ion

• E

mis

sion

inte

nsit

y •

Des

ign

life


Limited research has been carried out to establish a framework or project

appraisal as a guideline to ensure that sustainability criteria are embedded as early as

possible into the project design stage. Due to countless sustainability sets being

recognised, Fernández-Sánchez and Rodríguez-López (2010) produced a

methodology to identify sustainability indicators in infrastructure construction project

management based on risk management standards. These involved the participation of

every actor in the life cycle of a project. This allows for the identification and

classification of opportunities for improvement from the sustainable indicators in

every project phase. Even the proposed methodology was comprehensive in

identifying every single unique indicators, too many recognised indicators can be cost-

consuming for analysis and are often technically complicated to understand. Therefore,

important to realise that some of the indicators need to be excluded by prioritisation as

some opportunities could be physically or technically impossible to apply. Bocchini,

Frangopol, Ummenhofer and Zinke (2014) then strengthened the risk assessment

framework in both design and management of infrastructure systems in general to

enhance infrastructure sustainability development. They believed that resilience

should be complemented together to achieve the best possible quality of the

infrastructure. Compared to Fernández-Sánchez and Rodríguez-López (2010),

Bocchini et al. (2014) included the impact of service failure of the infrastructure into

the infrastructure resilience. This shows that the coverage of Bocchini et al. (2014)’s

study is beyond the service life while the former researchers only focus on the project

level. On the other hand, Morrissey, Iyer-Raniga, McLaughlin and Mills (2012)

developed an ecologically-sustainable appraisal framework for metropolitan

infrastructure projects by considering the opportunities to minimise the potential

impacts as early as possible in the design and planning stage. Unfortunately, this

appraisal scope may be limited as it was developed based on the urban infrastructure

development setting and predominantly concerned on the environmental perspective.

Instead of concentrating on city development, Zhang, Wu, Skitmore and Jiang (2015)

introduced decision-making framework for sustainable infrastructure projects in

balancing urban-rural development. Efficiency indicators and equitable investment

indicators were used to quantify the effect to the sustainability of infrastructure

projects. Although the study covers thirty projects over the country, only two types of

infrastructure projects were targeted which are water supply projects and road

construction projects. Within the limited scope of projects, Zhang et al. (2015) may


not be applicable to the other kind of infrastructure projects. Meanwhile, Lim (2009)

choose to concentrate on economic pillars which is one of the sustainability elements

that should be attended to. He established an integrated decision-making guideline for

sustainable infrastructure projects by adopting a concept used by Sahely et al. (2005)

that incorporates both socioeconomics and environmental sustainability, as shown in

Figure 2-2. This figure attempts to illustrate the interaction of infrastructure with the

natural and socio-economic environments. However, the limitations of this figure is

that it represents the process as a linear process, implicitly suggesting that the natural

environment provides resources that can be exploited through infrastructure to provide

needs for humans; and there is no feedback loop between the demand and the

environment. Overall, most of previous works have limited research scope such as a

specific type of project, a particular sustainability perspective or only focus on a

particular phase of project life cycle. Therefore, there remains a need to put the

deficiencies of previous studies into consideration and further integrating them to

produce a more holistic framework.

Figure 2-2: Infrastructure systems assessment framework

(Sahely et al., 2005)

As an outstanding issue in infrastructure development, especially in the project

delivery process and its operational system, sustainability concerns are paramount.

While sustainability strategies and frameworks have focused on wider aspirations and

strategic objectives, they are noticeably weak in addressing micro-level integrated

decision making in the built environment, particularly for infrastructure projects (Love

et al., 2010). In addition to improving the understanding of sustainability, Boyle et al.


(2010) acknowledged that urbanisation growth, increasing age of infrastructure, and

risk of failure in urban infrastructure, together with resource availability are the

challenges for developing a sustainable infrastructure framework. Accordingly, it can

be argued that the integrated application of sustainability principles in a built

environment should be studied more extensively. This would apply across all stages

of infrastructure project development, including design, planning, construction,

operation, and deconstruction phases.

2.2.4 Life Cycle of Infrastructure Development

A life cycle generally comprises a complete series of development processes

from the inception to the termination of services or products. According to the

International Organization for Standardization (2006), life cycle refers to “consecutive

and interlinked stages of a product system, from raw material acquisition or generation

from natural resources to final disposal”. The life cycle of project development

consists of a collection of phases that begins with project conception and initiation,

and is then followed by planning and design phases, project execution, operation, and

demolition. It plays a role as a fundamental structure for project management purposes.

Some researchers have provided specific categorisation for project life cycle

phases. For example, Watson et al. (2004) classified the life cycle for sustainable

building into five groups and explained each group individually, as follows:

1. Define phase - involves the strategic planning, project brief preparation, design

brief preparation, project intent and objectives, concept development, design

tender, tender developing, bid assessment, and planning approval.

2. Design phase - comprises of brief response, build information, preliminary

examination, objectives, brief, sketch/model development, assessment,

coordination, and specification.

3. Detail phase - includes establishment of sink/source data, industry details,

sensitivity analysis, eco-practice, eco-profile, consultancy, packaging, eco-

label, supply tags, and procurement.

4. Deliver phase - covers all the activities of supervision, demolition,

construction, fit-out, pre-occupancy, acceptance, operation, post occupancy,

performance, and maintenance.


5. Deconstruct phase - consists of the activities such as reuse, renewal,

refurbishment, renovation, relocation, redevelopment, recovery, recycling, and

deconstruction.

Pons and Aguado (2012) and Dong and Ng (2015) subsequently reflected the

“cradle-to-end” life cycle and disseminated it into several phases, beginning with

material extraction and ending with building demolition, as shown in Figure 2-3.

Figure 2-3: “Cradle-to-end” life cycle

(Adapted from Dong & Ng, 2015; Pons & Aguado, 2012)

Meanwhile, Quale, Eckelman, Williams, Sloditskie and Zimmerman (2012)

emphasised the importance of waste management as part of the life cycle assessment

phase in measuring the ecological impacts of different construction methods. Focusing

on built environment assets, such as building, Crawford (2011) simply classified the

life cycle into three main phases of manufacturing, use, and demolition, and specified

each phase, as featured in Figure 2-4.

Particularly in relation to sustainable infrastructure development, Dasgupta and

Tam (2005) categorised the life cycle of a project into three main phases: pre-project

planning, project implementation, and on-going operations. Pre-project planning

involves activities such as design, funding, and budgeting set up; while the

implementation phase incorporates the physical work execution. This is followed by

on-going operation, which covers built asset management, including financial,

planning, authorisation, and maintenance issues. Meanwhile, Lim (2009) classified an

infrastructure project development life cycle into seven processes, specifically:

conception, feasibility, design, construction, operation, maintenance, and disposal.


Figure 2-4: Life cycle of built environment assets

(Source: Crawford, 2011)

In spite of various categories and classifications for project life cycle phases,

they are all similar in terms of the sequence of activities. These common phases can

be simply classified into three major groups: the pre-construction phase, construction

phase, and post-construction phase. These three phases are clearly dependent on each

other, especially the later phases. As infrastructure projects provide long periods of

operation, the post-construction phase of infrastructure is very critical and should be

extensively considered in the early decision-making processes during the planning and

design development and the construction phases.

2.2.5 Sustainable Delivery of Infrastructure Project

Many researchers from various disciplines have explored the sustainable

delivery approach of infrastructure project development towards sustainability across

the project life cycle. A sustainable construction project is considered to have been

successfully delivered if it embraces a harmonious balance between environment,

economy, and social aspects. It also becomes a desired outcome for project

stakeholders during the decision-making process through the application of


sustainability principles and sustainability assessment throughout the infrastructure

project life cycle (Binney, 2014).

In order to accomplish the concept of sustainability in an infrastructure project,

Lim and Yang (2007) stated that every phase of its development has to be guided by

the principle of sustainable development, as shown in Figure 2-5. The design basis of

an infrastructure project must cover all phases of the project life cycle, including the

design phase, construction phase, in-place built phase, and the operation phase,

respectively (Gudmestad, 2015). This has led to efforts to not be limited to only the

identification of sustainable elements, but to also establish a sustainable approach to

be implemented and practised for promoting sustainable infrastructure development.

Figure 2-5: The conceptual framework of sustainable infrastructure development processes.

(Source: Lim & Yang, 2007)

Pre-construction phase

The pre-construction phase takes place in the earliest stage of infrastructure

project development. Once the infrastructure project is initiated, it is essential to firstly

recognise the most reliable procurement method to be adopted, as the selection and

cooperation of project stakeholders plays an important role in the project’s success.

The selection of a delivery system, financing approach, and payment mechanism must


provide the best value and benefits to the public (Abdel Aziz, 2007). At this stage,

sustainability principles must be incorporated into the project delivery life cycle in

order to guide policymakers, stakeholders, and community leaders to deliver more

reliable and resilient infrastructure (Binney, 2014). For example, implementation of

green procurement, strategic asset management, and relational contracting seem

promising for greater sustainability achievement (Lenferink et al., 2013).

Establishment of sustainability qualifications, awards, and contract performance

criteria early in the project development (planning and design activities) through green

procurement practices could raise private market and public project requirements.

Therefore, social and environmental commitments must be measurable and

incorporated into project documentation and contracts (Yates, 2014). However,

Lenferink et al. (2013) highlighted that operation and maintenance management have

to be synchronised effectively by redefining the role of government and private actors.

For this reason, introduction of relational contracts could be a favourable measure to

make project management more adaptive and sustainable to manage the complexity of

an infrastructure project, improve key player relationships, and smooth transaction

difficulties (Lenferink et al., 2013).

Apart from the issues of stakeholder relationships and cooperation arrangements

in the pre-construction phase, the decision-making process in the design stage is also

critical for project success. Gudmestad (2015) stated that an appropriate design basis

must be established in the early phases to ensure that the project is executed safely and

efficiently. Associated with large-scale population, acceleration of infrastructure

development could cause significant environmental deterioration through the high

consumption of raw materials and energy (Morrissey et al., 2012). For example, large

quantities of construction materials and waste generation, significant greenhouse gas

emissions from production and transportation of most consumed materials (e.g.

Cement and asphalt), and disturbance of natural habitats due to natural resource

extraction will result in a depreciation of the ecological balance. However, many of

these environmental implications can be identified and avoided in the early stage of

planning and design. The main emphasis in the design phase relates to the selection of

materials and the construction methods to be implemented. These are both important

factors in managing resource use to deliver a sustainable project.


Table 2-2 summarises the sustainable design strategies put forward by several

researchers that should be considered during the design stage of the construction

project. Swamy (2001) advocated a holistic-sustainable design and construction

approach that integrates the whole aspect, from conceptual design to completion and

maintenance. Despite having contemplated construction of new structures, Swamy

(2001) claimed that the existing structure has to include diagnostic evaluation to

measure the capabilities to regenerate, rehabilitate, retrofit, repair, and protect from

severe environment conditions or else justify the demolition. Highlighting the recycle

and reuse approach, and inspired by Kibert (1994), Crowther (2005) developed

principles of design for disassembly to improvise the transition from the construction

demolition phase to the disassembly phase. The focus of both design strategies

specifically signifies the environmental concerns, particularly on resource

optimisation, limited to design team principles. In order to increase the adaptability of

industrialised buildings, Sadafi, Zain and Jamil (2012) then developed strategies for

flexibility improvement. More recently, Yates (2014) included impact on community

and economic influence aspects in his design consideration by involving commitment

from all stakeholders. Moreover, it has been argued that issues of embodied energy

content, greenhouse gas emissions, and toxic generation during the production of

material should be investigated (Kibert, 1994). These technical criteria are very

influential in material selection process, especially from an ecological aspect. Go et al.

(2015) highlighted that multiple generation life-cycles of eco-design is an

advantageous strategy because it goes beyond one complete life-cycle that involves

disassembly, recycling, reuse, remanufacturing, refurbishment, or repurposing. This

design also has the ability for upgrade, assembly, disassembly, modularity,

maintainability, and reliability. Thus, the infrastructure will be functional over its

intended lifespan and possibly be prolonged. In addition, Sadafi et al. (2011) also

believed that adoption of industrial flexible and demountable design has the potential

to satisfy the tenets of sustainability by reducing the cost of operations and

maintenance. These can be achieved by allowing the buildings to be easily adapted

and changed. Overall, the construction materials to be created and used, and the

structures to be designed and built, should be environmental-friendly, cost-effective,

ductile, and have high durability for long life service (Swamy, 2011).


Table 2-2: Design strategies by various researchers

Authors Design

Approach Strategies/Criteria

(Swamy, 2001)

Holistic design: concrete construction

1. Design for cost effective durable performance and service life 2. Design for strength through durability rather than durability through

strength 3. Design for site waste minimisation 4. Reduce waste, recycle waste 5. Design for least damage to environment 6. Innovate design: closer analysis of design loads: avoid overdesign 7. Design for specified design life based on cost-benefit analysis 8. Design for dismantling, and reuse 9. Design for material stability and structural integrity.

(Crowther, 2005)

Design for Disassembly

1. Use recycle or recyclable material 2. Minimise the number of different types of materials 3. Avoid toxic and hazardous materials 4. Avoid composite materials and make inseparable subassemblies

from the same material 5. Avoid secondary finishes to materials 6. Provide standard and permanent identification of material types 7. Minimise the number of different types of 8. Use mechanical connections rather than chemical ones 9. Use an open building system where parts of the building are more

freely interchangeable and less unique to one application 10. Use modular design 11. Use construction technologies that are compatible with standard,

simple, and ‘low-tech’ building practice and common tools 12. Separate the structure from the cladding, internal walls, and services 13. Provide access to all parts of the building and to all components 14. Make components and materials of a size that suits the intended

means of handling and locating components during the assembly and disassembly procedure

15. Provide realistic tolerances to allow for manoeuvring during disassembly

16. Use a minimum number of fasteners or connectors 17. Use a minimum number of different types of fasteners or connectors 18. Design joints and connectors to withstand repeated use 19. Allow for parallel disassembly rather than sequential disassembly 20. Provide permanent identification of component type 21. Use a structural grid 22. Use prefabricated subassemblies and a system of mass production 23. Use lightweight materials and components 24. Permanently identify points of disassembly 25. Provide spare parts and on-site storage for them 26. Retain all information on the building construction systems and

assembly and disassembly procedures

(Sadafi et al., 2012)

IBS construction flexibility improvement

1. Provide detailed information about the connections and components 2. Encourage innovation in design 3. Simplify the erection and dismantling (less require special tools and

skills) 4. Employ standard connection


Authors Design

Approach Strategies/Criteria

(Yates, 2014)

Design for sustainable industrial construction

1. Use a green design rating tool or standard to set goals reflected in the contract documents.

2. Provide reasonable life cycle payback periods for design criteria. 3. Commit to achieving a certain level of certification and

incorporating it into all project documentation. 4. Consider impact on the community (construction through operations

and closure) in design decisions. 5. Measure sustainability achievements and publish case studies of

projects so others may use them as benchmarks. 6. Engage stakeholders in the design process and incorporate their

concerns. 7. Utilise life cycle cost analysis in value engineering approaches. 8. Consider pending regulations in design decisions. 9. Utilise tangible and intangible costs for carbon and other

environmental risks. 10. Include input from stakeholders into designs that evaluate

sustainable alternatives. 11. Utilise sustainable design guidelines to incorporate sustainable

alternatives. 12. Review all project systems for sustainable alternatives. 13. Involve contractors in sustainability constructability reviews. 14. Utilise building information modelling (BIM) to help monitor the

incorporation of sustainable strategies. 15. Evaluate the overall life cycle costs to provide data on first costs

versus life cycle costs and savings. 16. Explore sustainable alternatives by evaluating life cycle costs

including cradle-to-grave considerations. 17. Monitor the incorporation of sustainable alternatives based on life

cycle cost analysis rather than first costs.

Many researchers believe that the application of the life-cycle concept into

construction development could enhance project sustainability (Gu, Chang, & Liu,

2009; Russell-Smith, Lepech, Fruchter, & Meyer, 2015; A. Singh, Berghorn, Joshi, &

Syal, 2011; Watson et al., 2004). Watson et al.’s (2004) life cycle theory divides the

building life cycle into two different types: temporal design and physical building, as

shown in Figure 2-6. The first covers design processes and construction asset

management planning, while the other is related to material flows, from the initial

material extraction until material disposition back to the earth. He and Yin (2009) then

put forward a new concept of life cycle by considering the gaps between the predicted

and actual life period, as the deviation between them will greatly affect the decision-

making process for infrastructure operation and maintenance. Through their three

bottom line life cycle analysis, Eckelman et al. (2013) found that infrastructure

refurbishment is more desirable than replacement; however, this depends on its

maintenance and service life assumption. Not limited to construction products


selection and decision-making, life cycle assessment (LCA) is also applicable to

construction systems and process evaluation (Singh et al., 2011). For example, Dong

and Ng (2015) and Russell-Smith et al. (2014) used LCA to examine the environmental

impact during the upstream process of building construction. Unfortunately, a case

study conducted by Parrish and Chester (2014) found that LCA is commonly practised

for life cycle cost where the focus is only on the economic perspective. For a broader

and holistic life cycle impact, the anticipation of environmental and societal

consideration in LCA should become an integral part in sustainable infrastructure

development.

Figure 2-6: Temporal design versus physical building life cycle

(Source: Watson et al., 2004)

Apart from material innovation, many construction methods and approaches are

available to encourage sustainability practices. The practice of construction

industrialisation seems promising in promoting sustainable construction. A range of

building approaches has been studied to represent the application of industrialised

construction. These include, “prefabricated”, “precast”, “industrialised building”,

“off-site construction”, and “modularisation”. Other benefits of adopting construction

industrialisation include: a speed-up of the construction period (Pan et al., 2007),

reduction of manpower (CIDB, 2003, 2010), high flexibility (Thanoon, Wah Peng,

Abdul Kadir, Jaafar, & Salit, 2003), and better quality due to the controlled

environment of building component production. Dong and Ng (2015) also revealed

that adoption of precast components could reduce environmental pollution. With


regard to this, Yunus (2012) developed a decision-making guideline to assist designers

in promoting sustainable construction by optimising the value of the IBS.

Construction phase

The application of industrialised and prefabricated components not only

simplifies the construction process, but also enables waste minimisation through the

design and manufacturing process (Burgan & Sansom, 2006; Crowther, 2005; Tam,

Tam, Zeng, et al., 2007). Waste minimisation is very significant to environmental and

economic implications. Construction waste is commonly caused by eight main

sources, as shown in Table 2-3. This waste generation could be controlled and

eliminated by proper planning and appropriate construction practices. Gerth, Boqvist,

Bjelkemyr and Lindberg (2013) found that waste reduction could be achieved by

implementing lean construction procedures. Adopted from manufacturing industry,

the lean construction concept is about designing and operating the right resources at

the right time with the right system (Ahuja, 2013). The focus is on the improvement

of construction process efficiency through waste elimination and productivity

optimisation. This could enhance material utilisation through its key concepts, such as

the “just-in-time” concept, in reducing material damages (Ahuja, 2013) and the Kaizen

in waste elimination by empowering the responsibility, time, and skills of employees

(Nahmens & Ikuma, 2012). This was proven by J. Meiling, Backlund and Johnsson

(2012) and Nahmens and Ikuma (2012) using case studies where incorporation of lean

principles into construction industrialisation not only promoted resource optimisation

but also reduced safety risks and economic uncertainties. However, successful lean

application can only be attained with full commitment from top management,

sufficient involvement of technical and management experts, the awareness and full

dedication of workers, and a continuous improvement culture surrounding the project

team (Senaratne & Ekanayake, 2012).

Table 2-3: Different sources of construction waste (Source: Gerth et al., 2013)

Waste source Description Example

Overproduction Making more than is immediately required

Completing operations earlier than necessary, (e.g., painting of walls in rooms that are not completed)

Waiting Waiting for parts, information, instructions, and equipment

Blueprints are not finished when on-site operations need them


Waste source Description Example

Transport Moving people, products, and information

Inappropriate distances between storage, workplace offices on site owing to little logistic planning

Over-processing Tighter tolerances or use of higher quality in materials than necessary

Including more functions within the product than the customer wants

Inventory Storing parts, pieces, and documentation ahead of requirement

Unnecessary large storage of materials and

components on site

Motion Bending, turning, reaching, and lifting Inappropriate work conditions, (e.g., unnecessarily heavy and high lifts)

Defects Rework, scrap, and incorrect documentation

Rework of operations and construction material affected by climate

Unused employee creativity

Underutilising capabilities Not considering onsite experiences from earlier projects in new projects

Post-construction phase

Turning to the post-construction phase, this should cover the operation and

maintenance (O&M) activities. Operation refers to the activities involved in the

delivery of a service or building to be used with care. Meanwhile, maintenance refers

to the activities that ensure that the infrastructure remains in a serviceable condition to

ensure long-life service (Sohail, Cavill, & Cotton, 2005). Faludi, Lepech and Loisos

(2012) mentioned that energy impact during building operation is a very substantial

element for the promotion of more sustainable building. Unlike residential and

commercial buildings, building-type infrastructures of public facilities, such as

airports, hospitals, and schools exhibit obvious ongoing costs, particularly O&M costs.

Saghatforoush (2014) found that the costs of failure in the O&M phase of

infrastructure projects was more significant than in other project types. Building

characteristics and design problems, construction-related issues, maintenance-related

issues, and fast technological advances and high occupancy level issues tend to be the

causes of costly rework. These technical issues do not arise independently during the

post-construction phase, but tend to occur earlier during the preceding phases. For

example, many repair works during O&M phases are caused by design error, low

quality material, or poor construction work that occurs during the design and

construction phases. Saghatforoush (2014) pointed out that involvement of O&M

stakeholders in the early project phases could upgrade the operability and the

maintainability of the infrastructure. It seems that proper and strategic maintenance

management planning is essential to prolong the service life of built infrastructure.

This is because the lifetime of a long-lasting built infrastructure could reduce the


amount of resource demand and greenhouse gas emissions (Shi et al., 2012) through

material, transport, and energy consumption minimisation, as well as waste and

pollution control.

From this discussion, it is apparent that many methods of sustainable practice

could be applied in an integrated way in order to intensify the sustainability of

infrastructure projects in the future. The strategies and approaches presented in the

literature show the robustness of sustainability awareness during construction project

development. However, these kinds of approaches carry with them various well-

known limitations. Even though past research may have been carried out on a specific

building types, or even adopted a particular construction method, the lessons learned

in relation to infrastructure project development could still be applied in general,

especially those involving building-type infrastructures. Nevertheless, sustainable

criteria and requirements for every project phase need to be established as early as

possible during project initiation to ensure that it leads the decision-making process

for the following phases.

2.3 INDUSTRIALISED BUILDING SYSTEM (IBS)

2.3.1 Overview

IBS is a dominant terminology, particularly embraced by the Construction

Industry Development Board (CIDB) of Malaysia. It represents the application of

construction industrialisation through prefabrication, precast components, and/or off-

site construction. Looking forward to the evolution of the IBS concept in a global

perspective, it should expand to include the modularisation and hybrid construction

approaches (Kamar et al., 2011). A variety of terms are used to describe IBS

application in construction practices. Jaillon and Poon (2009) and Tam et al. (2007)

used the terms “fabricated building system”, “prefabrication”, and “prefabricated

building/component” interchangeably for standardised modular design buildings that

adopted pre-casting techniques with a high level of repeatability. Arif et al. (2010); N

Blismas, Pasquire, and Gibb (2006); Boyd et al. (2013); W. Pan et al. (2007); W. Pan

and Sidwell (2011); and Zhai, Reed, and Mills (2014a, 2014b) used the term “off-site

construction” to represent modern construction methods that move a part of the on-site

construction activities, such as in-situ concrete casting, into a manufacturing

environment prior to transport and assembly at the building location. Component


production processes pertaining to manufacturing, industrialisation, and industrialised

building/construction are other terms used by Ågren and Wing (2014); Larsson et al.

(2014); R. Schmidt, Vibaek and Austin (2014) and Zhang and Skitmore (2012) to

exemplify the standardisation in structure component design and production process.

Regardless of the multiple definitions and terms used, Kamar et al. (2011) revisited

the extensive definition of IBS as an innovative construction system that has at least

two of the following characteristics: (i) industrialised in transportation, production and

assembly, (ii) mass-production, (iii) on-site fabrication, (iv) standardisation and

structured planning, and (v) integration of the processes.

2.3.2 IBS Adoption in Malaysia

The introduction of the IBS concept in the Malaysia construction industry began

in the early 1960s, when the government initiated two pilot projects for an affordable

housing scheme (Abd Hamid, Chee Hung, & Abdul Rahim, 2017). The projects

involving the construction of low-cost flats. The government aimed to construct

quality affordable housing in a short period of time (Hamid, Kamar, & Alshawi, 2011).

This project used large panels pre-cast concrete walls and plank slabs. However, the

IBS application in the projects did not perform as expected, as the adoption of the

foreign system did not consider the Malaysian climate and social practices (Abd

Hamid et al., 2017).

In the 1980s and 1990s, the utilisation of steel components for building structures

gained much attention, especially in the construction of high rise buildings (CIDB,

2003). At the same time, high demand for new residential projects increased the

application of IBS, particularly the use of a precast concrete system. Accordingly, in

the mid-1990s, hybrid IBS, which involves a combination of multiple IBS systems,

was used in many national iconic infrastructures, such as the Kuala Lumpur (KL)

Convention Centre, Lightweight Railway Train, Mosque, KL Sentral Station, KL

Tower, KL International Airport, and Petronas Twin Tower (Abd Hamid et al., 2017),

as shown in Figure 2-7. The IBS systems adopted in these projects involved, but were

not limited to, steel beams and columns, precast hollow cores, roof trusses, and precast

concrete slabs.


Figure 2-7: Examples of hybrid IBS application in Malaysia

(Source: CIDB, 2017a)

The application of IBS in Malaysia is currently increasing. Local IBS

manufacturers and suppliers have grown from at least 171 in 2013 (MIDF, 2014) to

201 in 2015 (Tajul Ariffin, Yunus, Mohammad, & Yaman, 2017). They have acquired

enough knowledge and experience to develop their own IBS technologies. Due to the

growth in IBS technology, recent projects that have adopted IBS, such as hospitals,

colleges, and universities, government administration complexes, hotels, and

commercial buildings are excellent in terms of quality and architectural appearance

(Hamid et al., 2011).

Furthermore, IBS has been identified as one of the ways to move the Malaysian

construction industry forward (Abd Hamid, Kamar, & Bahri, 2013). The Malaysian

Government has launched many initiatives to promote and encourage the application

of IBS in the local industry, as summarised in Table 2-4.

Table 2-4: IBS-related initiatives by the Malaysian Government

Initiatives Description

IBS Strategic Plan 1999

‐ To make construction sustainable

‐ To be able to penetrate the global market

‐ To support and utilise knowledge-driven technology

‐ To raise the standard and quality of construction

‐ To produce a human-friendly built environment

IBS Roadmap 2003-2010

‐ Enforcement of utilisation of at least 50% of IBS content in the construction element for the government project (building) in 2005.

‐ Levy exemption for the contractors that use IBS with at least 50% as the construction components.


Initiatives Description

‐ Provision of tax incentives for manufacturers of IBS components

‐ The enforcement of using modular coordination (MC 1064) through uniform building by-laws (UBBL)

‐ Development of IBS verification scheme for IBS products and components

Construction Industry Master Plan 2006-2015 (CIMP)

‐ IBS Center as one stop centre for training, consultancy and showcasing IBS technologies.

‐ Stimulation of research and development activities and construction innovations

‐ Establishment of certified IBS manufacturers system.

IBS Roadmap 2011-2016

‐ Enforcement of utilisation of at least 70% of IBS content for public sector building projects

‐ Encouragement of utilisation of at least 50% of IBS content for private sector building projects

These efforts began with the establishment of the IBS Steering Committee in

1998 to bring forward all IBS-related issues in a framework to advance the

construction industry (Hamid et al., 2011). As a result, the IBS Strategic Plan 1999

was published to set a good framework for the successful upgrading of the Malaysian

construction industry and to maintain a competitive edge in the global market using

IBS (Hamid et al., 2011). Accordingly, in 2003 the IBS Roadmap 2003-2010 was

launched to facilitate the transformation of the Malaysian construction sector

according to the GoM master plan with the 5-M Strategy (manpower, materials-

components-machines, management-processes-methods, monetary, and marketing)

(CIBD, 2003). The commitment to IBS was further reaffirmed when the Malaysian

cabinet endorsed the IBS Roadmap as the blueprint to industrialise the construction

sector by 2010 (MIDF, 2014).

Under the Construction Industry Master Plan 2006-2015 (CIMP), IBS was

highlighted under one of the strategic thrusts to promote and encourage innovation in

construction techniques (CIDB, 2007). Many initiatives have been undertaken to

support and promote IBS application, such as the establishment of an IBS Centre as a

training hub, development of 7-modules of IBS professional courses, National

Occupational Skill Standard for Construction Industry courses for installers, as well as

research and development activities relating to IBS (Hamid et al., 2011; Nasrun et al.,

2011). However, the adoption of IBS in the private sector remains low (MIDF, 2014).

Subsequently, in 2011, a new IBS Roadmap 2011-2015 was published to impose high-


level intended outcomes of implementing IBS (Hamid et al., 2011). This roadmap

narrowed the objectives that focused on quality, efficiency, competency, and

sustainability (CIDB, 2010), in addition to streamlining the way forward for

sustainable IBS adoption in public and private projects (Hamid et al., 2011).

There are five categories of structural classification for IBS adoption in Malaysia

(CIDB, 2003), as shown in Figure 2-8.

Figure 2-8: Types of IBS systems

(Source: CIDB, 2003b)

Precast concrete framing, panels, and box systems involve the use of precast

elements that are produced in the casting yard, and are then transported to the

construction site to be assembled. The structural or architectural precast components

could be produced in a variety of shapes depending on the type of usage. These kinds

of components are usually precast beams, columns, slabs, staircases, and lift cores. For

example, this system was used in the construction of KL Monorail (rail transit system)

in 1990s (Hamid et al., 2011).

On the other hand, a prefabricated timber framing system is usually applied for

building frames and roof trusses. Bell (1992) claimed that this system delivers rapid

and economic construction while also providing good sound insulation and fire

• Precast column, precast beam, precast slab• 3D components (e.g., balcony, stairs, toilet, lift core)• Permanent concrete formwork

PRECAST CONCRETE FRAMING, PANELS AND BOX

SYSTEM

• Prefabricated timber frames• Roof trusses

PREFABRICATED TIMBER FRAMING SYSTEM

• Steel beams and columns• Portal frames• Roof trusses

STEEL FRAMING SYSTEM

• Interlocking concrete masonry units • Lightweight concrete blocksBLOCKWORK SYSTEM

• Tunnel forms• Beams and column moulding form• Permanent steel formwork (metal decks)

STEEL FORMWORK SYSTEM


resistance. The utilisation of prefabricated wood and wooden products could offer

appealing design features for aesthetic architectural design (Hamid et al., 2011).

Steel framing system is commonly used for speedier construction due to its

simplicity and buildability (Hamid et al., 2011). It is more practical for commercial

and industrial buildings, especially those that include high repeatability of standardised

components. This system is commonly used for beams, columns, portal frames, and

roof trusses (CIDB, 2003).

In addition, a blockwork system is the simplest, most flexible, and most versatile

system that can be used in any type of construction (Hamid et al., 2011). There are

several types of blockwork systems, such as interlocking concrete masonry units and

lightweight concrete blocks that are engineered and manufactured in some form of

standardised measurement. However, to capitalise on the benefits of this system, a

skilled designer is required to suit and complement this system with other IBS

technologies. Apart from the load-bearing element, this system is also suitable for non-

bearing walls, such as fencing and partitions.

Another type of IBS system available in Malaysia is a steel formwork system.

Unlike the other systems described here, the steel formwork system is the least

prefabricated-type of system (MIDF, 2014). This system involves cast in-situ using

steel formworks or moulds. The formworks can be used repetitively and very

economically for large-scale construction projects. In Malaysia, apart from being used

in building construction, this system is popular for the construction of tunnels because

it involves repetitive structural elements (Hamid et al., 2011).

The implementation of IBS in Malaysia is growing and improving in the

construction industry (Abd Hamid et al., 2017). As a result, there are a variety of

innovations and new technologies that involve material development and innovation

systems. Recently, the use of Design for Manufacturing and Assembly (DfMA) has

begun to gain attention in local construction industry. The principle of DfMA

incorporates the technological and economic feasibility for components’

manufacturing and assembly at the design stage to maximise the manufacturability and

the assemblability (Yuan, Sun, & Wang, 2018). According to CREAM (2018), a lot of

local IBS producers have moved towards DfMA application through Prefabricated

Prefinished Volumetric Construction (PPVC) manufacturing especially for housing

projects. PPVC is the new and an advanced modular construction technology whereby


free-standing volumetric modules complete with walls, floors and ceilings finishes was

constructed offsite, then delivered and ready to be installed on-site (BCA, 2014).

Perhaps, the evolution of IBS through such innovation can promote its implementation

more widely in near future.

The application of IBS in a particular project is not only subject to a specific type

of IBS system, it may involve a combination of several systems, also known as “hybrid

IBS”, to optimise the benefit of IBS application. However, each system has its own

weaknesses and advantages. Therefore, it is important to be aware of the system

capabilities and technologies available to ensure the application of the appropriate

systems, which will lead to successful IBS implementation.

2.3.3 IBS: Drivers and Limitations

Many studies (Bari, Abdullah, et al., 2012; Din et al., 2012; F. Ismail, Yusuwan,

& Baharuddin, 2012; Jabar, Ismail, & Mustafa, 2013; Kamarul Anuar Mohamad

Kamar, Alshawi, & Hamid, 2009; Kamarul Anuar Mohamad Kamar & Hamid, 2011;

Mohammad, 2013; Musa, Mohammad, & Mahbub, 2014; Rahim, Hamid, Zen, Ismail,

& Kamar, 2012; Yunus & Yang, 2014, 2012) have identified the drivers and

limitations of IBS implementation in diversified perspectives. According to the IBS

Roadmap 2003-2010, IBS guarantees better quality, productivity, and safety (CIDB,

2003). Boyd et al. (2013) found that off-site construction is responsible for

construction duration, ease of construction process, and quality control. Good quality

control during production of precast elements could improve the durability of

buildings (Jaillon & Poon, 2009). In addition to productivity and quality matters, a

comparative study by Jaillon and Poon (2008) also discovered other benefits, such as

optimisation of material consumption, low waste generation, high productivity with

less labour required, and promotion of health and safety. Japan is a leader in large-

scale industrialisation and considers prefabricated buildings to be the most customised,

reliable, technology-equipped, and properly designed buildings (Linner & Bock,

2012). It is apparent that adoption of industrialisation in the construction industry will

contribute to quality, productivity, efficiency, safety, and sustainability improvements.

However, Larsson et al. (2014) argued that reliance on these advantages is not

sufficient to drive industrialisation practices in infrastructure construction to survive

in the industry globally.


Cost and lead time are the most concerning factors of industrialisation in

infrastructure projects to capture the global market (Eriksson, Olander, Szentes, &

Widén, 2014; Larsson et al., 2014). However, Jaillon and Poon (2008) stated that

prefabrication does not contribute to project cost saving. This is influenced by high

initial cost for component moulds design, uneconomic for small scale production,

availability of low price local raw materials, and an excess of cheap foreign labour

(Lachimpadi et al., 2012; Tam, Tam, Zeng, et al., 2007). Yet, contractors involved in

design-bid-build contracts still tend to focus only on short-term project costs instead

of whole life-cycle expenses (Eriksson et al., 2014).

Even though minimal on-site activities will significantly expedite project

completion, initial design development of prefabrication application is time-

consuming. It is also inflexible regarding changes and invariability in the building

aesthetic (Tam, Tam, Zeng, et al., 2007). Moreover, a lack of consideration of

industrialisation application in the planning and design stage could result in limited

site space for placing and storing the prefabricated components (Jaillon & Poon, 2008;

Tam, Tam, Zeng, et al., 2007). This will override the advantage of off-site

construction, which is supposed to simplify the construction process. As higher quality

output is expected through factory-produced building elements, lack of manufacturer

or supplier skills and insufficient industry investment in research and development

could also impede the success of off-site construction practices (Boyd et al., 2013).

2.3.4 Sustainable IBS

Sustainable IBS construction can be described as IBS projects that have fulfilled

the triple bottom line principle. This terminology comprises three broad aspects of

sustainability, including environmental, economic, and social attributes (Lim & Yang,

2007). However, in an attempt to integrate sustainability into IBS, Yunus and Yang

(2012) sub-divided sustainability into four dimensions: economic, environmental,

social, and institutional. Sadafi et al. (2012) found that the expansion of industrialised

construction and prefabrication in a controlled environment allowed issues of

sustainability to be addressed more quickly and efficiently. This statement is consistent

with Kamar et al. (2011) who argued that IBS has the potential to promote

sustainability from a controlled production environment, minimise waste generation,

use energy-efficient building materials, promote effective logistics, and encourage

economic stability and sustainability.


From an environmental perspective, performance factors to be considered for

construction method selection include material and energy consumption (during

production, construction and transportation), waste management, site disruption,

pollution (by transportation and production), and regeneration ability (Chen et al.,

2010b; Quale et al., 2012). Prefabrication is considered a solution to waste problems

on a construction site (Tam, Tam, Zeng, et al., 2007). Dong and Ng (2015) and Bari et

al. (2012) believed that savings in natural and energy resources could reduce

environmental destruction. Cao, Li, Zhu and Zhang (2015) claimed that prefabricated

construction could contribute to a 36% reduction in resource depletion. This finding

seems consistent with Aye et al. (2012), who showed that a reduction in consumption

of raw materials could be achieved up to 50% in weight. The differences in that

saving’s percentage can be explained by the different types of raw material used.

Despite this, production of components or construction material is carried out in a

manufacturing environment. Resources, including raw materials, are utilised only at

the required level. Bari et al. (2012) also found that adoption of interlocking blocks

and prefabrication systems would reduce material consumption where the construction

of structural framing can be eliminated. Thus, construction costs could also be reduced.

On the other hand, research carried out by Jaillon et al. (2009), Jaillon and Poon (2008),

and Lawson et al. (2012) found that either modularisation or prefabrication techniques

could significantly reduce up to 70% of waste generation, with greater opportunity of

recycling. This could be achieved by substitution of timber formwork with reusable

and recyclable steel formwork at the manufacturing plant, and elimination of

plastering, tiling, and on-site concrete work. During the IBS construction phase, less

on-site activities would significantly minimise noise and dust pollution (Ahn & Kim,

2014; Jaillon & Poon, 2008), providing a cleaner and neater working environment, as

all wet trades are done off-site. The implication of off-site fabrication is that it could

minimise the possibility of waste generation at the construction site. Furthermore,

comparative studies by Aye et al. (2012) and Nematollahi, Voo and Saifulnaz (2014)

showed that embodied energy in a prefabricated building is greater than in a

conventional-built building. This is consistent with Lawson et al. (2012) who claimed

that waste reduction is directly proportional to the embodied energy of the construction

material. Above all, Zhai et al. (2014b) found that elements related to the environment

are the major drivers of IBS.


In terms of economy, Lawson et al. (2012) highlighted that sustainability factors

involve both direct and indirect costs. Expenditure on production facilities investment,

the cost of materials and production processes, as well as transport and installation

costs are quantifiable factors. Meanwhile, the efficiency of the material used and the

manufacturing process, the proportion of on-site activities, benefits of speedy

installation and minor repairs, as well as savings in site management account for the

intangible costs. According to Chen et al. (2010b), the most significant economic

performance criteria in construction are project duration, initial investment,

constructability, material costs, and lead times. Case studies by Jaillon and Poon

(2008) and Yu, Al-Hussein, Nasseri and Cheng (2008) revealed that the construction

cost of using prefabricated systems was slightly higher than conventional construction.

This might be influenced by the initial investment in prefabrication facilities,

professional design consulting fees, and additional logistics costs, which can be up to

20% of the total build cost (Lawson et al., 2012; Mao et al., 2016).

However, in contrast, a survey conducted by Polat (2008) found that more than

90% of contractors agreed that cost savings could be achieved through a precast

concrete system. This may be explained by the fact that the contractor does not spend

money on manufacturing facilities investment and simply hires a minimum amount of

labour for on-site construction activities. Even so, better quality control under the

manufacturing environment and use of advanced materials substantially contributes to

life cycle cost savings. For example, the use of fibre-reinforced polymer composite for

prefabricated components has reduced life cycle cost due to less maintenance being

required and an expanded service lifetime (Sebastian, 2013). In addition, a recent case

study by Ahn and Kim (2015) found that the efficiency and productivity advantage of

modular construction could expedite project completion by up to 30%. At the same

time, construction lead-times could be reduced, as prefabrication and site preparation

occur almost simultaneously. Production of components is also independent of adverse

weather consequences. Ahn and Kim (2015) also claimed that high quality

prefabricated components could reduce energy consumption over the operational

phase, thus reducing the occupant’s energy bills. These findings are in accord with

Merritt, Mccullough and Burns (2005) who found that road construction using an IBS

approach could save money, avoiding continual and frequent maintenance. From the

above scenarios, it can be seen that over the life cycle of the construction project,


greater performance in terms of construction duration, quality, productivity, and

energy efficiency outweighs high investment at the initial phase of the project.

Moreover, other potential cost reductions, such as less on-site activities, less on-site

labour required, and optimisation of resources management contribute to the economic

pillar of sustainability (Jaillon & Poon, 2008).

Nevertheless, social effectiveness is essential to achieving sustainability as a

whole. Chen et al. (2010b) indicated that the social aspect of the selection of a

construction method could be divided into two elements: the architectural impact and

health and community impact. It is essential to ensure that the selected building method

has minimal impact on the workers and surrounding community. For IBS

implementation, Jaillon and Poon (2014) reported that less than 16% of labour is

required at a construction site. For this reason, site-intensive accident rates could be

reduced by up to 80% (Lawson et al., 2012). The excessive number of on-site workers

has been replaced by the workers at the manufacturing yard. However, they are

provided with better working conditions in a controlled environment. The safety of

workers is subsequently enhanced by removing them from inclement weather and

exposure to extreme temperatures (Ahn & Kim, 2014). Another social concern

involves the safety and comfort of surrounding residents. Nuisances caused by on-site

construction activities, such as noise, dust, and traffic congestion may cause conflicts

with the local community (Ahn & Kim, 2014). Lawson et al. (2012) emphasised that

a reduction of up to 50% reduction in noise and disruption could be achieved through

modularisation. Moreover, frequent delivery trips of materials and equipment from

multiple suppliers for cast in-situ activities are minimised by ready-to-install

components transportation delivery (Chen et al., 2010b), which provides better traffic

conditions. Turning to the second element, advanced automation technologies used in

IBS could offer aesthetic solutions from various design innovations and also in terms

of the precision and consistency of end product quality. As such, the use of non-

concrete material, such as steel and composites, provides an advantage in terms of the

flexibility of fabrication (Chen et al., 2010b). Moreover, Peris Mora (2007) claimed

that modular-style buildings provide a convenient modification for future maintenance

or renovation works. Jaillon and Poon (2008) then found that improved quality and

durability through prefabrication application could be used to solve maintenance

issues, such as debonding tiles, thus ensuring occupier safety. However, other social


criteria, such as adaptability to change and occupant health and safety (Chen et al.,

2010b; Pons & Aguado, 2012) toward IBS implementation have not yet been

researched. Above all, the evaluation of each sustainable factor should be extended,

not only to the construction stages, but also examining the operation and maintenance

of the built assets.

As far as limitations are concerned, to raise broader awareness of

industrialisation practices in infrastructure projects, Larsson et al. (2014) mentioned

that industry, clients, and the government should break down the barriers related to

conservatism, lack of repetition, norms and codes, procurement practices, and

regulatory framework. For this reason, the institutional element in sustainable IBS is

essential to nurture human interactions, such as those existing between the regulation

system and society (Yunus, 2012). Thus, the perspective and implication to

construction stakeholders as the project player and the public as the occupier must be

explored when assessing the applicability and practicality of industrialisation in


Based on the above findings, sustainable IBS involves the integration of

sustainable elements that cover every aspect of the project life cycle. Prior to this,

Yunus (2012) implied that, to deliver sustainable IBS, enabler setting during project

initiation is essential to be the motivator towards the establishment of integrated

decision-making guidelines, followed by sustainable IBS design. It is therefore

apparent that the implementation of IBS in infrastructure projects is inspirational and

feasible to stimulate sustainable infrastructure development.

2.3.5 Delivery Strategies of IBS Implementation

Once the project has been initiated, the first step is to decide the most appropriate

project delivery system. According to Syed Zakaria, Gajendran, Skitmore and Brewer

(2017), the procurement setup and management approach for a particular project may

influence the IBS adoption decision. This early project decision is crucial, especially

for new IBS practitioners to incorporate knowledge and collaborate communication in

construction procedures, which could prevent potential conflicts and disputes later on

(Jelodar, Jaafar, & Yiu, 2013). According to Ahn and Kim (2014), in contrast to the

traditional procurement system where contractors are not involved in this phase, the

IBS-based project requires their participation from the beginning of the project’s

development. Contractors and designers should work together at this stage to achieve


successful constructability application of IBS. Long term procurement that integrates

asset management, such as design-build-finance-maintain and design-build-maintain

would provide better operational and maintenance management and planning in the

future (Sebastian, 2013), while also integrating the downstream value chain of

components and materials with the suppliers and manufacturers. It is also important to

note that the selection of the component fabricator should not only be based on

competence in terms of experience, specialisation, and expertise, the location of the

fabrication yard and financial ability would also be essential advantages (Ahn & Kim,

2014).

The substantial design factors for IBS are standardisation and repetition of

components and design (Burgan & Sansom, 2006; Jaillon & Poon, 2010). To recognise

standardisation possibilities, it is crucial to opt for IBS at an early design stage (Tam,

Tam, & Ng, 2007). Many researchers have discovered and merged the concept of

sustainable design into IBS implementation. Chen et al. (2010b) demonstrated the

primary strategies of prefabrication application and optimisation by designing a

construction method selection model, which only works for concrete buildings.

Notably, material selection is a key element in IBS application. However, it is

advantageous to integrate more than one type of material. In such a hybrid system, the

strength of material properties of a particular material type can complement the

weaknesses of the others (Hein, 2014). Beyond this, Faludi et al. (2012) suggested the

use of alternative materials to replace cement, as the source of this raw material is

becoming incrementally depleted. Moreover, other materials, such as steel (Aye et al.,

2012), timber (Hein, 2014), laminated bamboo lumber (Mahdavi Clouston, & Arwade,

2012), and composites (Hong & Hastak, 2007; Sebastian, 2013) have proven to

provide great performance as structural components. Most recently, De Brito et al.

(2016) found that recycled concrete aggregate could be used in new concrete

production without downgrading its performance. This provides recycling options for

precast rejects, thus reducing natural resources consumption and landfill disposal. For

a long sustainable lifespan, Erkelens, Jorritsma, Wagemans and Clement (2009)

claimed that flexibility and adaptability should be incorporated into design features.

Lehmann (2011) then stated that designers should take into consideration material

flow, material recovery, and adaptive re-use to deliver sustainable buildings. These

factors are directly associated with material and energy efficiency. Therefore, material


recovery through a closed loop material flow and selection of long-life materials were

recommended by Yunus and Yang (2013) to achieve more ecologically sustainable

IBS construction. Go et al. (2015) also proposed designing for upgrade, assembly,

disassembly, modularity, maintainability, and reliability as the operative eco-strategies

for re-adaptive use. The use of wet trade between precast component should be avoided

(Burgan & Sansom, 2006; Jaillon & Poon, 2014), while innovative dry-joint

connectors such as bolt connections are recommended for use for a quick and accurate

joint (Burgan & Sansom, 2006; Chica, Apraiz, Rrips, Sánchez, & Tellado, 2011; Liu,

Bradford, & Lee, 2015). Employing standard connections while keeping records of its

detail information would support future adaptability (Sadafi et al., 2012). However,

the constructed structures have to be readily available for inspection work or

dismantling purposes without causing damage to other components (Burgan &

Sansom, 2006). Above all, design optimisation must also minimise the energy impact

during the in-use phase (Faludi et al., 2012) and include economic costs

(manufacturing, logistics, and maintenance cost) as a part of the consideration for

sustainability accomplishment (Canto-Perello, Martinez-Garcia, Curiel-Esparza, &

Martin-Utrillas, 2015; Martí, García-Segura, & Yepes, 2016).

Similar to conventional construction, the construction phase takes place after the

planning and design stage. However, with IBS application, the construction phase

involves components production, logistics, and the assembly process (Kamali &

Hewage, 2016). IBS components are produced under a controlled manufacturing

environment, providing systematic handling and storage of material, repetitive

production works, and minimal safety hazards (Boyd et al., 2013). In addition,

manufacturing instruments deliver precise cutting, accurate measurement, and

schematised forming procedures to enhance resource optimisation (Ahn & Kim,

2014). According to Pons and Wadel (2011), production optimisation could reduce

energy consumption and carbon emissions. This could be accomplished by targeting

zero waste, regenerating resources, using renewable energy, and an efficient logistics

arrangement. Senaratne and Ekanayake (2012) emphasised that the development of

the precast concrete bridge beam production process, which adopts lean principles,

could enhance production efficiency and also lead to long-term benefits. This may be

explained by the fact that space and resources are utilised at an optimum level by

eliminating unnecessary activities (Senaratne & Ekanayake, 2012). Easier access to


tools, fewer material deliveries, and better sequencing of crews could also enhance

productivity (Ahn & Kim, 2014; Boyd et al., 2013).

Prior to the installation process, IBS components need to be delivered to the

construction site. Logistics management is extremely critical in the construction phase.

The delivery and transportation of components from the fabrication yard requires

effective communication and arrangements to avoid delays in installation works. “Just-

in-time” is one of the lean techniques recognised as sustainable strategies to increase

logistics efficiency (Ahn & Kim, 2014). Just-in-time requires minimal inventory and

reduces transportation costs, as the materials are used immediately upon arrival (Wu

& Feng, 2012). This also leads to reducing carbon emissions by eliminating

transportation to and from the storage yard. On the other hand, coordination and

communication between the supplier, designer, and contractor are crucial to ensure the

supply chain and installation work remains on track. Such logistics management is

more appropriately placed at the factory rather than on-site (Boyd et al., 2013).

However, there should be effective communication with site representatives about the

on-going installation progress.

Subsequently, installation work also requires good and smart practices to secure

sustainable construction. Even though the IBS application requires a minimal number

of on-site workers, employing highly skilled and specialised work crews is important

to avoid mistakes, damage, and re-work during the assembly process (Ahn & Kim,

2014). While off-site fabrication has removed in-situ concreting hazards, working with

machinery and at height during installation works requires risk mitigation, as it

contributes to the social aspect of sustainability. Dewlaney and Hallowell (2012)

presented risk mitigation strategies that reduce the safety risk for high-performance

sustainable projects. Meanwhile, concerning safety issues, Ramírez Chasco et al.

(2011) illustrated that comprehensive application procedures of the IBS application

solve the limited working space problem. Achieving a high level of efficiency requires

smart and effective communication, coordination, and integration between key players

in the construction phase. For this reason, Zhong et al. (2015) developed the physical

internet-enabled building information modelling platform to integrate and synchronise

prefabrication production, logistics, and on-site assembly during the IBS construction

process.


After the construction phase is completed the built assets are ready for operation.

During this phase, facilities management and maintenance planning take over. Several

studies have been conducted to promote a high level of maintenance and operation of

built assets. Kim, Hong, Ko and Kim (2013) investigated the energy efficiencies of

multiple remodelling construction methods for future building expansion and precast

composite structural systems were recognised as the most energy saving method

compared to the reinforced concrete wall type of steel frame system. Wood (2012)

developed a professional overview of maintenance that may be required over the

building lifespan, and found that integration of processes, life, people, and materials

are important to conceptualise efficient maintenance methods and priorities. At some

point during operation, along with the proper maintenance, rehabilitation would be

demanded to increase market value by improving energy efficiency and operability

(Sousa, 2013). Refurbishment and retrofitting works offer considerable potential to

prolong and upgrade the building’s lifetime (Hrabovszky-Horváth & Szalay, 2014;

Langenberg, 2013). According to Lahdensivu, Varjonen, Pakkala and Köliö (2013),

components such as balconies and façades are easily deteriorated due to exposure to

the outdoor climate. It would therefore be advantageous to use the IBS method of

construction, where the principle of adaptability and flexibility could be adopted.

However, the components of the prefabricated elements need to be available over the

lifespan of the structure (Sebastian, 2013). Moreover, the materials’ capacity for repair

works, construction innovation, and the relevance of building functionality after

extended use should be considered in relation to both economics and feasibility

(Langenberg, 2013). Though IBS application demonstrates the adaptability

opportunity of existing buildings in many sustainable ways, these can only be

employed with forethought at the design stage. These findings show that the process

of IBS application is complex at every project phase. Therefore, IBS construction

should underpin the interrelationship between project phases, to strategize systematic

and organised project development.

2.4 IBS APPLICATION IN INFRASTRUCTURE PROJECTS

2.4.1 Overview

IBS adoption is increasing in construction development, especially in multi-

storey residential and commercial buildings. It has been recognised as the construction


technology that contributes to productivity improvement and environmental

preservation (Zulkifli, 2014). IBS has been practically implemented in the construction

of multi-storey residential and commercial building projects (Boyd et al., 2013; Jaillon

& Poon, 2008; Lawson et al., 2012; Lee, Kim, & Lim, 2014) in which the concepts of

standardisation, repetition, and prefabrication are recognised. That is a reason why

industrialisation is not very familiar in several types of infrastructure projects due to

the “unique in nature” identity (Eriksson et al., 2014). The application of the

industrialisation concept has emerged in construction innovation. Boyd et al. (2013)

introduced a unitised building that adopted an off-site construction approach as a

resolution to short-term lodging for buildings. By employing an SMLsystem (small,

medium, and large), Serra Soriano, Verdejo Gimeno, Diaz Segura and Meri De La

Maza (2014) proposed a modular house, designed with prefabricated and industrialised

elements built by assembly activity instead of construction. In addition, Lawson et al.

(2012) found that the cellular approach in modular technologies is not limited to

certain forms of building types, as long as the selection of suitable material is critically

considered during the design stage. Moreover, in his design for disassembly guide,

Crowther (2005) proposed the utilisation of interchangeable building parts using a

modular design, prefabricated sub-assembly, and mass-produced systems,

respectively. These kinds of components provide the disassembly ability of a

constructed building to improve future resource recovery.

A limited number of researchers have examined the type of construction

approach adopted in infrastructure projects. Construction industrialisation through

standardisation of products and processes is quite challenging in a project-oriented

environment for some kinds of infrastructure developments (Larsson et al., 2014).

With the exception of buildings, IBS application in other types of infrastructure

projects is not familiar, even though it has been implemented. Larsson et al. (2014)

suggested that certain components and subsystems are suitable for standardisation and

prefabrication adoption, as shown in Figure 2-9. The introduction of accelerated bridge

construction with the application of prefabricated components such as decks, piers,

abutments, walls, and girders has removed cast-in-place activities (Hällmark, White,

& Collin, 2012). This could minimise site works, reduce construction time, and

provide a safer work environment. For example, the replacement of the old Parkview

Avenue Bridge in Michigan adopted a fully prefabricated element system and


delivered significant cost and time savings (Attanayake, Abudayyeh, Cooper,

Mohammed, & Aktan, 2014). Although it is only applicable to limited elements,

adoption of prefabrication promotes the desired project cost-effectiveness, time

efficiency, and sustainability. However, due to the unique nature of infrastructure

projects, not all project stakeholders are keen to adopt construction industrialisation,

because it requires standardisation of products, processes, and methods (Eriksson et

al., 2014).

Figure 2-9: Products, subsystems and components of infrastructure identified as being suitable for standardisation and prefabrication

(Source: Larsson et al., 2014)

Prefabricated technologies are not only restricted to concrete, but also include

steel and timber. According to Larsson et al. (2014), tunnel lining, noise barriers,

retaining walls, edge beams, bridge foundations, and permanent concrete casting

moulds are other appropriate components that could be standardised and prefabricated

using not only concrete, but also steel for reinforcement. As steel and cement

consumption for infrastructure maintenance is expected to remain high in the future,

effective uptake innovations in construction technology are essential, not only to

reduce material consumption intensity (Shi et al., 2012), but also to improve project

performance (Rose & Manley, 2012). For example, industrialisation construction

technologies have to be implemented via closed-loop phases of design, production,

assembly, and disassembly (Pons & Wadel, 2011). Go et al. (2015) suggested that

consideration for disassembly, recycling, reuse, remanufacturing, refurbishment, or


repurposing might go beyond one life-cycle. However, life cycle design approaches,

such as DfD (designed for disassembly) and IFD (industrialised, flexible, and

demountable) were seldom found to be practised, even though they were

acknowledged as resource optimisation solutions (Jaillon & Poon, 2010).

Above all, these findings indicate that adoption of IBS in infrastructure projects

is feasible. At the same time, infrastructure development must respond to the

requirements of sustainable development. Excluding IBS application in building

construction, research on IBS application and its adaptability for various types of

infrastructure projects is still behind. Larsson et al. (2014) believed that through

similarity recognition among projects and the exploration of repetitiveness and

standardisation, opportunities could be found to encourage industrialisation practices

in infrastructure development. Thus, further research should be conducted to bridge

the characteristics of construction industrialisation and project-oriented features of


2.4.2 Drivers and Challenges of IBS in Infrastructure Projects

In order to learn about and apply insights regarding the application of IBS in

infrastructure projects, it is essential to explore the drivers and challenges.

Prefabrication application is time-consuming in the initial design development. It

requires very careful planning, as it is inflexible in relation to design changes (Tam,

Tam, Zeng, et al., 2007). Moreover, a lack of consideration regarding IBS application

in the planning and design stage would result in limited site space for placing and

storing the prefabricated components at a construction site (Jaillon & Poon, 2008;

Tam, Tam, Zeng, et al., 2007). These issues may offset the advantages of off-site

construction, which is supposed to simplify the construction process. As higher quality

output is expected through factory-produced building elements, a lack of manufacturer

or supplier skills, as well as insufficient industry investment in research and

development, also impedes the success of practice (Boyd et al., 2013).

Through a comparative study between precast and conventional construction

through an industry-wide survey, Jaillon and Poon (2008) discovered other benefits

that could encourage the application of IBS, such as optimisation of material

consumption, low waste generation rate, high productivity with minimal manpower,

and promotion of health and safety. However, reliance only on these advantages is not


adequate to drive IBS practice in infrastructure construction to survive in the industry

globally (Larsson et al., 2014).

Subsequently, cost and lead time are the most concerning factors of

industrialisation in infrastructure projects to increase the global market (Eriksson et

al., 2014; Larsson et al., 2014). Jaillon and Poon (2008) pointed out that prefabrication

does not necessarily contribute to project cost savings. There may be a high initial cost

for component moulds design, uneconomical scenarios for small scale production,

availability of low price local raw materials, and an excess of cheap foreign labour

(Lachimpadi et al., 2012; Tam, Tam, Zeng, et al., 2007). In addition, contract ors that

are involved in design-bid-build contracts tend to focus only on short-term project

costs instead of whole life-cycle expenses (Eriksson et al., 2014).

As far as limitations are concerned, there are potential risks that affect the

perception of practitioners toward the use of IBS. Luo et al. (2015) identified “poor

cooperation between multi-interfaces”, “lack of management practices and

experience”, “inappropriate design codes and standards”, “enormous difficulty for

return on high initial investment”, and “lack of quality monitoring mechanism for the

production process” as the major risks for the IBS implementation. Meanwhile,

Larsson et al. (2014) mentioned that industry, clients, and the government should act

in their roles to break down barriers of conservatism, lack of repetition, norms and

codes, procurement practices, and the regulatory framework to nurture broader

awareness of promising strategies to implement IBS in infrastructure construction

projects.

Even though some of the IBS drivers and challenges discussed above are

generalised regardless the type of construction projects, at some points, they could be

argued depending to the project type, the design of physical structure, location of

projects, budget limitations, procurement system as well as the objective of a particular

project. For instance, the commercial building projects which located at a new

development area probably do not face with challenges of limited space for component

storage purpose compared to the construction of railway transit in the traffic area.

Other than that, the architectural design of an airport may require higher aesthetic look

than the design of a school. Aesthetic looks may involve specialized and exclusive

designs, therefore it may become a challenge for the consultant to apply IBS for such

projects. Therefore, perspectives of construction stakeholders should be explored in


assessing the consideration factors, applicability and practicality of IBS in


2.4.3 IBS Innovation and Technology in Infrastructure Projects

IBS, as one of the modern construction methods, is a constantly evolving

innovation in the construction industry. The application of the IBS concept is widely

implemented in developed countries such as Japan, United Kingdom, and Hong Kong

(Bock & Langenberg, 2014; Canfora, 2011). Nowadays, developing countries are

utilising greater with the implementation of IBS through various innovative

construction technologies to improve construction project efficiency.

As sustainability becomes a major concern in the construction industry,

numerous innovations in the sector are being developed to embrace the challenges.

According to Glavind (2014), innovations in the construction industry work towards

improvement in execution processes, reduction of environmental impacts,

performance enhancement, and/or improvement in the life of services, and thereby also

improve the level of sustainable development. In the case of IBS, innovations can be

found in either material development, or system and design improvement.

Most built structures consist of concrete and steel reinforcement. As concrete

and steel usage is expected to remain high in the future for infrastructure and building

maintenance, construction technology innovation is essential to reduce consumption

intensity (Shi et al., 2012). For example, Hong and Hastak (2007) studied the

suitability of fiber-reinforced polymer as replacement bridge deck panels and found

that it was more effective than precast concrete, and its inherent advantages in term of

lightness, strength and stiffness are recommended for immediate rehabilitation works.

However, that material is not a cost-effective option unless significant development in

the initial material cost has been refined (Hong & Hastak, 2007). On the other hand,

Mahdavi et al. (2012) used the economic-low-technology production process to

fabricate 4-ply laminated bamboo lumber, allowing it to be produced wherever

bamboo was planted. Laminated bamboo lumber was also found to be mechanically

suitable as structural components (Mahdavi et al., 2012). Most recently, Loss, Piazza,

and Zandonini (2015a, 2015b) demonstrated a hybrid construction that involves a

combination of structural elements made of different materials, such as steel and

timber. Both timber-to-timber and steel-to-timber connections are joined using special

dry mechanical devices, therefore working effectively even in harsh climatic


conditions. Additionally, the advantages of intrinsic deformation capacity of steel

material complements the use of lightweight material of cross-laminated timber to

deliver a lightweight modern seismic-resistant construction. Even though these

innovations do not directly demonstrate the development of IBS, advancements in

these building materials could offer great potential for the development of a more

efficient construction approach.

IBS can be applied to a wide range of building forms, such as school buildings

(Edelman, Vihola, Laak, & Annila, 2016; Pons, 2011; Rabeneck, 2011), commercial

or industrial buildings (Henry & Ingham, 2011; PCI, 2007), and residential buildings

(Cao et al., 2015; Meiling et al., 2014; Mirsaeedie, 2012; Nahmens & Ikuma, 2012;

Rocha et al., 2015). Multiple innovations in IBS have also been introduced over time.

Boyd et al. (2013) introduced the unitised building concept, which adopted off-site

construction as a resolution to short-term lodgings for buildings. Serra Soriano et al.,

(2014) proposed an SMLsystem (small, medium, and large) by assembling

prefabricated and industrialised modules to build SMLhouses. Rather than using

construction, the SMLhouse modular concept allows connection through an easy and

quick process that adopts a ‘plug and play’ system. This system clearly reflects

sustainable architecture through its design, modularity, flexibility, and prefabrication.

These creative modifications and adaptations allow IBS implementation to suit the

purpose of the building and the uniqueness of the construction project. Not limited to

building structures, IBS can also be utilised in bridge construction through the concept

of the accelerated construction technique. This approach, also known as accelerated

bridge construction (ABC), uses prefabricated bridge elements (PBE) and requires

particular mechanisation techniques for the installation process (Hällmark et al., 2012).

Notably, the precast concrete foundation (PCF) system, developed by the University

of Alberta and associates, demonstrates that IBS applicability is not limited only to

superstructure construction (Yu et al., 2008).

On the other hand, the evolution of and attention to IBS is recognised through

the expanding research works on this topic. Extensive and critical reviews of IBS

practices on management (Li, Shen, & Xue, 2014), design and production (Go et al.,

2015; Jaillon & Poon, 2014), and performance (Kamali & Hewage, 2016) could be

among the credentials for robust and ideal IBS implementation.


2.4.4 IBS Research Agenda in Promoting Sustainable Infrastructure

This section reviews the publications from 2005 to 2016 that contribute to the

body of knowledge under IBS-sustainability-infrastructure themes. Three authoritative

databases comprising of Science Direct, Scopus, and the American Society of Civil

Engineering (ASCE) library were utilised. The ASCE database was used because it

covers publications in all aspects of civil engineering. Scopus and Science Direct were

used as they provide interdisciplinary research databases through Elsevier. Falagas,

Pitsouni, Malietzis and Pappas (2008) found that Scopus covered a wider journal range

and outperformed other search engines in term of search accuracy, compared to Web

of Science, Google Scholar, and PubMed. Scopus has also been used in previous

studies (Hong & Chan, 2014; Osei-Kyei & Chan, 2015; Yi & Yang, 2014) for research

trend reviews on construction-related topics.

The target papers were obtained by multiple combinations of search terms

among “IBS”, “sustainable”, and “infrastructure”, as comprehensively discussed in

Section 3.4 A total of 134 papers were found to be relevant, of which 111 papers

satisfied the search term combination of “IBS-Sustainability”, 19 papers for the

combination of “IBS-Infrastructure” and four papers covered all the three themes, as

shown in Figure 2-10. These numbers indicate that even though there are many

sustainability studies on IBS, very limited studies have focussed on its application in

infrastructure projects. Therefore, there is a need to examine current industrial

practices and the perspectives of industry players and professionals regarding the

adoption of IBS in an infrastructure project.

Figure 2-10: Number of relevant papers according to the combination of search themes


The relevant papers were examined using content analysis and simple statistics

to visualise the distribution and development of the research activities to date. It was

found that there were progressive research works from the first six years to the second

six-year period, as shown in Figure 2-11. The thorough literature review conducted

found that IBS innovations evolve with material development and system or design

improvement, and that sustainable practices are actually embedded in the principle of

IBS. Optimisation of material and energy used in IBS contribute to the environmental

preservation. Health and safety concerns, as well as aesthetical looks, are the

constructive factors that promote the social sustainability. Moreover, the relevance of

IBS towards economic prosperity is the productivity improvement through minimal

labour requirements, reduced construction duration, and better quality of construction.

Moreover, the findings from this review suggest that the selection of valuable material,

considering the re-adaptive use of design, adoption of lean principle during logistics

and installation works, employing skilled workers, and good facilities management

raise sustainable practices to a higher level. However, the integration of strategies at

each phase of the project life cycle and effective communication within project players

are crucial to ensuring that project delivery achieves the sustainability aims.

Figure 2-11: Distribution of published papers from 2005 to 2016


Through lessons learned from building construction, this review found that IBS

is also applicable and feasible in other types of infrastructure projects. Benefits such

as material optimisation, high productivity, and low waste generation could outweigh

the challenges of expensive initial investment, and a lack of standard and codes

practices. However, many questions have been raised and require further investigation.

It is recommended that future research be undertaken in the following areas: (1) the

adaptability and practicality of IBS in infrastructure projects, (2) the sustainability

performance evaluation of IBS application in infrastructure development, and (3) the

development of IBS deliverable guideline for infrastructure projects’ stakeholders. It

would also be valuable to assess IBS application in regards to specific types of

projects, to acknowledge particular issues and challenges.

2.5 NURTURING SUSTAINABILITY THROUGH INFRASTRUCTURE REDEVELOPMENT

2.5.1 Concept of Redevelopment

Redevelopment has an emphasis on the post construction stage, which involves

activities such as renewing, revitalising, reconstructing, recovering, refurbishment,

renovation, or replacement. These activities could assist in optimising the remaining

life cycle of existing built assets (Shah & Kumar, 2005). Moreover, the initiative of

deconstruction and recovery encompasses issues such as building components and

building structures to be reused, and recovery, disassembly, and recycling options

(Watson et al., 2004). These can all assist with avoiding demolition and waste

generation.

The sound performance of infrastructure determines the capability of those

facilities to serve the public sustainably to cater to a growing population. Teriman,

Yigitcanlar, and Mayere (2010) claimed that rapid population growth and developing

cities create demand for expansion on infrastructure and services, such as high-

frequency public transit and other high capacity urban infrastructures. These factors

triggered a redevelopment project of a subway station in Boston (Highfill, Shah,

Brenner, & Formosa, 1996). This project involved station expansion by the addition

of new subway lines and facilities enhancement (e.g., lengthening platforms,

improving handicapped access, and refurbishing the signals and tracks). In addition, it

also involved station renovation to deliver a fresher look for a modern subway station.


Similarly, to increase the ridership of public transport in Kuala Lumpur, a

comprehensive upgrade and rehabilitation of existing infrastructure, which included

constructing new lines, extending existing lines, extending pedestrian walkways,

expanding parking facilities at terminals, and revitalising terminal hubs was initiated

by the Government of Malaysia (Economic Planning Unit (EPU), 2015b). According

to Zavadskas and Antuchevičiene (2004) revitalisation of buildings not only promotes

sustainable development and improves the quality of life towards economic goals, but

also helps to preserve natural and social environments.

Transformative renewal is one of the key tenets in promoting sustainable urban

development. It can be undertaken through the implementation of adaptive reuse,

which utilises the existing building for different functions than the current one (Lewin

& Goodman, 2013). For example, the development of a university campus in

downtown Windsor by retaining the original historical building gave a new-unique

identity to that city (Lewin & Goodman, 2013). Wide-ranging benefits were attained

from this project. Through a building retrofit, energy efficiency was optimised by

improving the building envelope and upgrading mechanical and electrical systems.

Embodied energy stored in the existing buildings was also conserved by avoiding

demolition and reconstruction activities. This transformation also promoted land

conservation and revitalised part of the city

In addition, replacement is another option for redevelopment that may be caused

by certain issues of obsolescence in built assets (Langston, 1994). Subsequently, He

and Yin (2009) presented various obsolescence factors particularly based on lifecycle

categories, including technical life, social life, legal life, economic life, function or

service life, and physical life, respectively. Technically, the whole building or

buildings’ components dictate replacement due to superior technology development.

This is consistent with economic reasons to achieve the least cost alternative for

building operation and maintenance. Legal obsolescence due to safety rules and

building ordinance revision also leads to building replacement. Once the building

structure is no longer physically fit to serve its current building function or if the

service period is over (very old building), either major rehabilitation or replacement

should be considered. Changes in trends in society, such as the preference of

transportation service mode may lead to the need for renovation or replacement of

transportation service hubs.


In this regard, a case study by Eckelman et al. (2013) demonstrated that

refurbishment offers a better solution than replacement from both environmental and

economic assessments. Building refurbishment and upgrading are recognised as

sustainable approaches in a built environment by re-using and re-energising the

existing building instead of it being left unattended and remaining in a wearisome state.

Refurbishment is not limited to re-life for an aged building; however, from an

architectural advantage, it does keep the building attractive by transforming it to a

more stylish and modern look (Gorse & Highfield, 2009). It also supports excellent

opportunities to reduce energy consumption in buildings (Mickaityte, Zavadskas,

Kaklauskas, & Tupenaite, 2008). However, Setunge and Kumar (2005) mentioned that

the decision-maker should consider several factors before calling for a refurbishment

option decision, such as functional obsolescence, current performance, residual life

status, benefit-cost assessment, sustainability impacts, strategies and approaches, and

also future performance enhancement.

2.5.2 Redevelopment Contribution towards Infrastructure Sustainability

In this research context, redevelopment is a re-life process of an asset that may

involve activities such as reconstruction, refurbishment, renewal, renovation,

replacement, repair, revitalisation, modification, upgrade, and expansion. It is hard to

turn back once the physical infrastructure is in place. This is why the future

development and redevelopment options for urban infrastructure must be considered

earlier, as the longevity of physical life will impact upon energy consumption

(Morrissey et al., 2012). For example, transport infrastructure, such as railway stations

might be necessary for such redevelopment to cater to population growth demand, to

improve the services provided, to refurbish for a fresher look, and even renovation for

restructuring or rebranding purposes. Consequently, insufficient services with sub-

standardised, old infrastructure and vehicles are also recognised as the need arises to

upgrade the facilities and expand capacity (Tezer, Caliskan, Calik, & Sinmaz, 2010).

Activities such as refurbishment, repair, modification, and renovation of built

infrastructure are also part of maintenance works during service provision. These

activities absolutely deal with challenges related to service operation, especially if they

involve long-duration projects. Schedules, methods, and approaches for these

activities have to be properly planned and strategized to avoid service disruptions. As

much as possible, work activities should move away from the built structure by using


modular and pre-manufactured components (Ross, 2000). It is apparent that by

implementing IBS as the method of construction, the building or component

replacement or upgrading process will be simplified. On the other hand, the demand

for infrastructure accessibility presents greater challenges for planners and

infrastructure developers, not only to optimise the limited existing resources, but also

to provide reliable and sustainable infrastructure.

2.6 CONCEPTUAL RESEARCH FRAMEWORK

This background review of the literature indicates that development of IBS has

emerged to correspond with the needs of the construction industry. IBS provides a

productive and efficient approach, thus benefitting construction project objectives:

cost, time, and quality. Thus, IBS has been promoted as an innovative construction

method and sustainable solution for the construction industry. IBS carries significant

drivers, such as reducing build time, labour reduction, a cleaner site, less waste,

improving construction quality and safety, and reducing disturbance to the public.

These benefits assist in making a project more sustainable, and address the three

sustainability pillars: environment, economy, and social.

Despite this being thoroughly justified, there are concerns related to the

application of IBS in infrastructure projects other than the multi-storey buildings. As

most previous research has concentrated on IBS application in construction of multi-

storey buildings, little is known regarding whether its application in other

infrastructure projects is truly in accordance with the performance of IBS in such

projects. The applicability of application, and the limitation and the delivery strategies

of IBS in infrastructure projects as a whole are still questionable.

Accordingly, through this systematic review, three aspects were formed as the

foundation to promote the application of IBS. These comprise of drivers and

limitations, innovation and technology, and delivery strategies. These three aspects

then indirectly correspond to the potential of sustainable practices in project

development. The interrelatedness of these aspects guided the researcher to develop a

conceptual research framework, as represented in Figure 2-12.


Figure 2-12: Conceptual research framework

The conceptual research framework shown in Figure 2-12 attempts to integrate

IBS implementation in multi-storey buildings into infrastructure projects. From the

comprehensive literature review conducted, it was recognised that IBS had enjoyed

success in delivering sustainable construction, especially in multi-storey buildings

through the benefits of standardisation, repetition, and prefabrication. In the discussion

above (see Section 2.3.4) the sustainability of IBS was interpreted from its application

in building-type construction. Having that in mind, another categorisation of

construction projects which is infrastructure need to be attended to for establishment

of the more project-specific framework. Furthermore, Eriksson et al. (2014) believed

that the ‘unique in nature’ of infrastructure project characteristics restrains

industrialisation application in the project implementation. Therefore, the applicability

and adaptability of IBS in infrastructure projects remain to be explored.

The discussion in the previous section highlighted that the three concerns for

successful delivery of IBS application - namely drivers and limitations, innovations

and technology as well as delivery strategy – indicate that adoption of IBS in

infrastructure projects is feasible and practical. Despite having potential benefits in

general, the dotted line in Figure 2-12 shows that the implication of IBS to the

sustainability of infrastructure projects are still undiscovered. It should be noted that

the framework incorporated the three sustainability pillars individually, so that every

unique potential for each pillar can be identified correspondingly and comprehensively

based on the current practices in various infrastructure projects. Then, they are able to


be integrated and synthesised from different dimensions and points of views in a

holistic manner. This conceptual framework provides a good basis for the

establishment of research strategy – probe into the issues that need to be addressed,

find out particular concerns and thus fill up the gap between IBS deliverables and

infrastructure projects.

To achieve a holistic chain of achieving infrastructure sustainability, due

attention must be given to find effective ways and develop practical guidelines to

enhance sustainable foci during project delivery. This is achieved by integrating the

viewpoints of multi-character stakeholders that involved in multi-types of

infrastructure projects. Through their common understanding and consensus, this

research develops a framework that is able to guide stakeholders through their

decision-making processes.

2.7 SUMMARY

This section presented the relevant literature to justify the rationale of this study

and the identification of the research gap. The importance of sustainability

development requires conclusive initiatives by the construction industry to embed

sustainability principles in all project development, including infrastructure projects.

IBS has been identified as a modern construction approach to achieve better outcomes

in terms of quality, cost, and time savings. The potential of IBS for promoting

sustainable construction was also acknowledged, especially in terms of resources and

environmental preservation. The specific drivers and limitations of IBS applications

were also emphasised. Through a comprehensive literature review, a preliminary

conceptual framework was established to represent the interdependency between IBS,

infrastructure, and sustainability.

It is remarkable that there is very limited research focusing on the utilisation of

IBS in infrastructure projects to promote sustainable deliverables, even though IBS

has long been used for various infrastructure projects. For this reason, considering the

uniqueness of the construction industry in every country, it is important to investigate

the concerns of implementing IBS in the context of Malaysian infrastructure projects

and explore how Malaysian infrastructure project stakeholders address these concerns,

as only then can appropriate strategies for implementing IBS in infrastructure projects

be developed.


Examining the potential of sustainable IBS, a significant body of literature

discussed the capacity of IBS to nurture sustainability through infrastructure

redevelopment. It explored the definition and concepts of redevelopment and

highlighted its contribution to enhance infrastructure sustainability. However, to what

extent and how IBS could be optimised for redevelopment purposes is not well

documented. Thus, the above questions and arguments require further exploration and

investigation.

Chapter 3: Research Design and Methods 71

Chapter 3: Research Design and Methods

3.1 INTRODUCTION

This chapter describes the design and methods applied in this research to explore

the research problem and answer the research questions. After conducting a systematic

literature review, this study combined qualitative and quantitative methods to achieve

the specified research objectives. It employed a combination of interviews with

industry experts and a two-round Delphi study with experienced practitioners and

researchers in Malaysia. Both primary and secondary collected data were analysed to

establish a generic exploration of the application of IBS in infrastructure projects and

to form a sustainable framework. The chapter is organised, as follows:

Research philosophy

Research design and planning

Data collection and analysis method

Research rigour and validity

3.2 RESEARCH PHILOSOPHY

Research approaches involve a philosophical assumption about the study topic,

research design, and research methods. Saunders, Lewis and Thornhill (2009)

mentioned that the issues underlying data collection techniques and analysis

procedures have to be explored by peeling away each of the important layers of the

research “onion” (Figure 3-1) before an accurate choice can be made.

72 Chapter 3: Research Design and Methods

Figure 3-1: The research “onion”

(Adapted from Saunders et al., 2009)

Designing a research strategy involves three main components, including

research philosophical worldviews, strategies of inquiry, and research methods

(Creswell, 2014). Philosophical ideas assist the researcher to identify suitable

approaches that will be used for the research by understanding the basic ideas of

research nature. The philosophical worldview was also defined by Guba and Lincoln

(1994) as a “research paradigm” that has four different categories based on the nature

of research and that are shaped by the researcher’s discipline area, as shown in Figure

3-2.

Figure 3-2: Four research worldviews

(Adapted from Creswell, 2014)


Post-positivism is a deterministic paradigm used to identify and assess the

factors that affect results. This philosophy attempts to use existing theory to develop

hypotheses (Saunders et al., 2009). It is driven by a test of theory, data, and evidence

collection to either support or refute theories, and finally develop a relevant statement

to be tested for its validity and reliability (Creswell, 2014). Highly structured, with

careful observation and measurement for data collection purposes, this paradigm is

strongly related to quantitative approaches (Fellow & Liu, 2008). Constructivism is

also known as interpretivism and is contrary to post-positivism. It is typically seen as

a qualitative research approach relying as much as possible on participants’ views. The

subjectivity of varied human interpretation allows the researcher to look for broader

and more complex perspectives (Creswell, 2014). This process leads the researcher to

in-depth investigation (Saunders et al., 2009), in order to build a theory by generating

the data inductively.

On the other hand, a transformative worldview does not only limit the practice

in qualitative research, but could also be a foundation for quantitative research as well.

It also overrules the post-positivism assumption that structural laws and theories do

not fit marginalised individuals in society (Creswell, 2014). Intertwined with politics

and a political agenda, this paradigm brings advance changes of action agenda. In

contrast, pragmatism might work well to deal with variation in the research questions

(Saunders et al., 2009). The application of qualitative and quantitative methods are

combined to find a solution for the research problems caused by actions, situations,

and consequences (Creswell, 2014). This paradigm, which concentrates more on

research problems, prefers to adopt multiple approaches to determine the best

practicable solution.

After reviewing and understanding the various philosophical approaches,

appropriate and accurate strategies and methodologies can be selected (Saunders et al.,

2009). Based on the research problems (Section 1.2) and research objectives (Section

1.4), the aim of this research is to explore the application of IBS in infrastructure

projects and develop a framework to optimise the redevelopment potential of built

infrastructure through IBS application. Thus, the constructivist paradigm was deemed

the most applicable approach to this study, as the focus of this research is to discover

and understand the grounds of a concept, and also to delve into the concept in

comprehensive detail. Crabtree and Miller (1999) conceptualised the cycle of


constructivist inquiry by means of a closed-loop circle that involves the processes of

“invention/design”, “discovery/data collection”, “interpretation/analysis”, and

“experience/anomaly”. This cycle should be reinforced by a definite theory or

explanation, as shown in Figure 3-3.

Figure 3-3: Diagram of Constructivist Inquiry

(Adopted from Crabtree & Miller, 1999)

This research firstly developed a conceptual framework to guide the formulation

of expectation or questions relating to the study. A review of theories related to the

research subjects was also carried out, as it contributed to the development of the

conceptual framework for this research. According to Fellow and Liu (2008), bodies

of theory must be examined and evaluated so as to provide the basic structural

framework in order to determine and clarify facts and the interrelationship between

them. Thus, the relevant insights and interpretations from the project players were

blended with the assembled theories. Towards the end of the research, the manner in

which the theories interpreted the research findings, together with its applicability in

other studies are also presented.

3.3 RESEARCH DESIGN AND PLANNING

Research design is a logical and concise procedure that drives the specific

research direction by establishing the appropriate research inquiries among qualitative,

quantitative, or mixed method approaches. It is essential to primarily demonstrate the

strategies and approaches that will be adopted in the research to ensure that it is sound


and feasible to be carried out (Marshall & Rossman, 2016). The researcher recognised

the overall strategy for this research, which coordinated the research questions,

research objectives, and expected research outcomes with the data collection and

analysis methods, as shown in Table 3-1. This research is qualitatively designed, as it

focuses on a single concept of phenomena that deals with in-depth investigation

through theoretical and philosophical reviews.

Table 3-1: Selection of research methods

Research Questions Research

Objectives

Data Collection

Method

Data Analysis Method

Expected Research Outcome

RQ1: What are the perceptions of the construction industry with regard to IBS application in infrastructure projects?

RO1: To explore the current status of IBS application in infrastructure development.

-Literature review -Interview -Delphi study Qualitative

analysis for literature review and interviews – Nvivo Version 11

--------- Quantitative for Delphi Study – IBM SPSS 23

--------- Data triangulation

General understanding, drivers and challenges of IBS application in infrastructure project.

RQ2: What are the important elements/factors of infrastructure projects to apply or adopt IBS?

Consideration of factors for implementing IBS in an infrastructure project.

RQ3: How can IBS application contributes to infrastructure sustainability?

RO2: To identify the contribution of IBS application to infrastructure sustainability.

-Literature review -Interview -Delphi study

Performance and attributes of IBS application towards sustainable infrastructure.

RQ4: How can redevelopment potential promote IBS application in infrastructure projects?

RO3: To examine the potential of IBS application in facilitating the redevelopment of built infrastructure.

-Literature review -Delphi study

Adaptability and changeability criteria of IBS, and IBS strategies to facilitate the redevelopment of built infrastructure.

RO4: To develop a framework of sustainable IBS application for infrastructure projects.

-Literature review -Interview -Delphi study

A framework of sustainable IBS application for facilitating redevelopment for infrastructure projects.

3.3.1 Qualitative Design

Qualitative design research is based on constructivist perspectives. This

approach seeks to gain a better understanding by investigating what is occurring in the

problem nature (Maxwell, 2013). Qualitative data have been found to work best for


research that aims to discover, to explore a new area, and to develop hypotheses

(Amaratunga, Baldry, Sarshar, & Newton, 2002). The design of qualitative research

should be reflective and flexible throughout the research process, ready to modify the

data collection and analysis activities and the developed theory, as well as the research

questions, as these may affect and be affected by one another. According to Creswell

(2014), the initial research plan cannot be tightly prescribed. The key is to focus and

to learn about the problem or issue from participants instead of the researcher’s

thoughts and the literature. The research design should be flexible, as on-going

research input may lead the flow of the research over time.

Maxwell (2009) presented an interactive model of research design, based on the

coherency among five components (goals, conceptual framework, research questions,

methods, and validity) without strictly fixing and directionalising the sequence order,

as shown in Figure 3-4. This interactive design is systematically conceptualised, in that

every element has multiple connections among them instead of being in linear or cyclic

form. However, Fellow and Liu (2008) also mentioned that in addition to the research

questions and constraints, other factors, such as measurement instruments, reliability,

and validity requirements, must also be considered in order to underpin the selection

of approaches and strategies.

Figure 3-4: Interactive model of research design

(Adopted from Maxwell, 2009)


It is important to recognise the research goals that will encourage the researcher

to undertake the study. In addition to personal goals, Maxwell (2009) highlighted that

there are two types of additional goals to justify a study: practical goals and intellectual

goals. Practical goals are about fulfilling the needs of someone/something or changing

a certain situation. On the other hand, intellectual goals concentrate on understanding

the surroundings, as well as gaining some insight about how and why a particular

situation is happening. In the same way, this study aimed to explore new insight into

the precise nature of the research background. These intellectual goals led the study to

be conducted inductively, using an open-ended strategy to address numerous practical

goals. These included generating understandable and experientially credible results

and theories for the people being studied and others to contribute to improvement in

existing practice by conducting a formative study and engaging in collaborative

actions, or empowerment research with practitioners or research participants

(Maxwell, 2009).

A qualitative approach may generally employ various types of inquiry strategies,

such as narratives, phenomenologist, ethnographers, grounded theory studies, or case

studies (Creswell, 2014). According to Saunders et al. (2009), the selection of

applicable strategies should be based on the research questions and objectives, the

extent of existing knowledge, the time and resources available, and the philosophical

underpinnings.

In this study, the researcher applied the adaptive theory introduced by Layder

(1998b). Adaptive theory attempts to use a combination of pre-existing theory and

theory that emerges from data analysis in the research process. The dual influence

between these theories may involve both inductive and deductive procedures for

manipulating and developing theory. This research strategy could be between

subjective and objective perspectives, which may emphasise the theory discovery

through data interpretation and the reformulation of new theory through the

employment and adjustment of the extant theory (Layder, 1998a). This means that this

research not only explores but also explains what is going on.

This study employed multi-method qualitative studies, using multiple data

collection approaches, including a literature review, semi-structured interviews, and a

Delphi study. A detailed discussion of the data collection and analysis method is

presented in the following section. In conclusion, the overall approach taken for this


research can be summarised based on the research “onion” adapted from Saunders et

al. (2009), as shown in Figure 3-5.

Figure 3-5: Overall research approach

3.3.2 Research Process

Figure 3-6 provides an overview of the logical structure of the research. The

research processes were divided into three main phases. Briefly, the first phase

involved the establishment of a theoretical basis from the preliminary literature review

and formulation of the preliminary framework based on an extensive literature review.

At this stage, generic understanding was established to conceptualise the research

outcome. During the following phase, interviews were conducted with experts to

firstly validate the preliminary framework and explore the IBS applications in

infrastructure projects. At the same time, the perceptions of the practitioners towards

IBS application were also determined. A Delphi study was then undertaken to further

identify, validate, and prioritise relevant factors recognised from the literature review

and interviews until a reliable consensus of opinion was achieved. The findings from

the literature review, interviews, and Delphi study were triangulated to integrate the

in-depth understanding, related issues, solutions, and recommendations. The third

phase was the ultimate process where the established guideline was finalised. Finally,

the conclusions and recommendations drew upon this research accomplishment.


Figure 3-6: Research process flowData Collection Method


Data collection is an important phase in research studies. It is a process of

collecting and assembling information. Data may come in many forms, such as

literature, interview recordings, audio, photographs, reports, etc. Fellow and Liu

(2008) referred to data collection as a chain of communication between the respondent

(the provider) and the researcher (the collector). There are two types of

communication: either one-way or two-way communication. The former only requires

either acceptance or rejection of the data provided. Meanwhile, two-way

communication permits feedback from the provider to derive further information. It is

necessary to indicate what types of data are to be collected before deciding on a data

collection mechanism.

Qualitative studies require considerable amount of time for assembling multiple

types of research data. Observations, interviews, document archival, and audio-video

recordings have been conducted to accumulate qualitative data. Each mechanism has

its own advantages and limitations, as shown in Table 3-2. A combination of

mechanisms, on the other hand, can focus on their relevant strengths.


Table 3-2: Qualitative data collection: Advantages and limitations (Adapted from Fellow & Liu, 2008)

Data Collection Mechanism

Advantages Limitations

Observations • Researcher has a firsthand experience with the participant.

• Researcher can record information as it occurs.

• Unusual aspects can be noticed during observation.

• Useful in exploring topics that may be uncomfortable for participants to discuss.

• Researcher may be seen as intrusive.

• Private information may be observed that researcher cannot report.

• Researcher may lack good attending and observing skills.

• Certain participants may present special problems in gaining rapport.

Interviews • Useful when participants cannot be directly observed.

• Participants can provide historical information.

• Allows the researcher to have control over the line of questioning.

• Provides indirect information filtered through the views of interviewees.

• Provides information in a designated place rather than the natural field setting.

• Researcher’s presence may bias responses.

• Not all people are equally articulate and perceptive.

Documents • Enables a researcher to obtain the language and words of participants.

• Can be assessed at a time convenient to researcher – an unobtrusive source of information.

• Represents data to which participants have given attention.

• As written evidence, it saves the researcher the time and expense of transcribing.

• Not all people are equally articulate and perceptive.

• May be protected information unavailable to public or private access.

• Requires the researcher to search out the information in hard-to-find places.

• Requires transcribing or optically scanning for computer entry.

• Materials may be incomplete.

• The documents may not be authentic or accurate.

Audio-Visual Materials

• May be an unobstructive method for collecting data.

• Provides an opportunity for participants to directly share their reality.

• It is creative, in that it captures attention visually.

• May be difficult to interpret.

• May not be accessible publicly or privately.

• The presence of an observer may be disruptive and affect responses.


Qualitative researchers have described three main purposes for this type of

research: to explore, to explain, or to describe (Marshall & Rossman, 2016). The nature

of this study is exploratory, as it gathers the preliminary information and takes well-

defined theories and applies them in a research context. It relies on secondary research

that reviews the literature or data or collects the opinion and perceptions of the relevant

research participants. It builds rich descriptions of complex settings that are

unexplored in the literature (Marshall & Rossman, 2016).

The selection of an appropriate data collection mechanism depends on the types

of information required to answer the research questions. Robson (2002) provided

simple rules to choose the method based on what the researcher is looking for, and

these are presented in Table 3-3. As previously shown in Table 3-1, the first and second

research question are both ‘what’ type of questions. According to Yin (1994), survey

and archival analysis are the most common strategies adopted for such questions.

Surveys may be conducted in several ways, such as by using questionnaires or

interviews. However, in qualitative research, interviews are the most common methods

used (Gill, Stewart, Treasure, & Chadwick, 2008). Therefore, this research conducted

literature reviews, interviews, and a Delphi study (questionnaire approach) as the

sources of data in achieving the research objectives.

Table 3-3: Rules of thumb for the selection of the data collection method

Purposes Recommended Methods

1. To determine what they think, feel, and/or believe.

Interview, questionnaire or attitude Scales

2. To determine what they do in private. Interview or questionnaire

3. To determine what people do in the public. Direct observation

4. To determine their abilities, or measure their intelligence or personality.

Standardised tests

3.3.3 Data Analysis

Data analysis involves the process of examining, assembling, testing, or merging

qualitative and/or quantitative data to address the research questions (Yin, 2006). Once

the researcher has obtained the necessary research data, the analysis of the collected

data is carried out concurrently with an on-going data collection process. In this


research, the researcher carried out both qualitative and quantitative data analysis.

Qualitative analysis refers to the analysis of systematic literature reviews and the

interview data, while quantitative analysis was found in the Delphi study. Finally, data

triangulation was used to gain holistic insight for the purpose of achieving the research

objectives. The processes of data analysis for each approach are discussed in the

following sections.

3.4 LITERATURE REVIEW

The first stage of this research was the preliminary literature review. This was

undertaken to understand the research background and identify potential gaps in the

literature on a specific topic. Moreover, the literature review assisted the researcher in

ensuring that the selected topic was worthy of being studied, as well as providing

insight about the limitations of the research scope (Creswell, 2014). Three main themes

were selected: industrialised building systems (IBS), sustainability, and infrastructure.

From the thorough knowledge of these themes, the research questions, research

objectives, and scope were established. The literature review was carried out through

various sources, such as journal articles, conference proceedings, and reports within

the corresponding research settings.

In addition to the literature review, a comprehensive systematic review was

carried out to provide a clearer overview of the primary research that reflected the

research questions. A systematic review is a systematically structured methodological

procedure in which literature is thoroughly identified, assessed, and synthesised. There

are many differences between a conventional literature review and systematic review,

as presented in Table 3-4


Table 3-4: Difference between systematic and traditional review (Perry & Hammond, 2002)

Systematic review Traditional review

Uses a set search strategy Uses no set search strategy

Several pre-defined databases are searched in a systematic manner

Often not a systematic review of several databases

Can be replicated by another independent researcher

Cannot be replicated

Minimises bias Contains bias

Often involves a team of researchers Involves one researcher

Conclusions based on a series of set and pre-defined outcome measures

Conclusions based on findings of the studies found in the search

The systematic review was carried out in three stages, as illustrated in Figure

3-7. In Stage 1, the researcher used three main themes for the literature search based

on the background of this study. The themes were: “sustainability”, “infrastructure”,

and “IBS”. The search terms used for IBS were prefabricat* building/construction,

industrial* building/construction, modular* building/construction, pre*cast

construction, and off-site construction. The researcher also used a combination of these

terms within these themes to retrieve more refined papers. Two sets of theme

combinations were used for the paper retrieval: (1) IBS and infrastructure, and (2) IBS

and sustainability. In Stage 2, the search scope was narrowed to limited subject areas

of engineering, social sciences, environment science, management, decision sciences,

and design. In Stage 3, each relevant article was visually scanned through the abstract,

introduction, and conclusion to ensure that only corresponding papers were retained.

Classification analysis and content analysis were then conducted.


Figure 3-7: Systematic review process

The systematic literature review in this research aimed to discover the

progressive research coverage and study the body of knowledge under IBS-

sustainability-infrastructure domains. Correspondingly, the objectives were to

discover the themes and patterns of the previous research on IBS application in

infrastructure projects, and to subsequently explore its contribution to sustainability

aspiration. Furthermore, the researcher sought to describe the characteristics or


components of infrastructure projects that could accommodate IBS application. At the

same time, by comparing the existing evidence of IBS contribution to sustainable

construction, the researcher pursued recognition of research opportunities in delivering

a sustainable infrastructure.

3.5 INTERVIEW

An interview is an insightful discussion that involves at least two people to

collect relevant and reliable research data. Saunders et al. (2009) divided interviews

into two main categories: standardised interviews and non-standardised interviews. A

standardised interview, also known as a structured interview, is typically used for

quantitative data collection using interviewer-administered questionnaires.

Meanwhile, non-standardised interviews are more modifiable. They may use multiple

forms of communication, as shown in Figure 3-8.

Figure 3-8: Forms of interviews

(Adopted from Saunders et al., 2009)

Interviews may also be categorised into three types: structured, semi-structured,

and unstructured. Structured interviews operate with a list of predetermined questions,

while unstructured interviews are conducted freely without a specific flow of

questions. Intertwined between these, semi-structured interviews are designed with

several main predetermined questions to guide the flow of conversation. Relevant or

potential sub-questions also are prepared by the researcher. However, not all of the

predetermined questions will necessarily be voiced during the interview session. The


flow of questions can be modified, omitted, or added based upon the participants’

responses and what seems most appropriate (Robson, 2002).

The rationale for using semi-structured interviews in this research was based on

going beyond answering questions of “what”, and also answering “why” (Saunders et

al., 2009). This research was highly exploratory, because there is limited a priori

information regarding the application of IBS on sustainable infrastructure projects.

The interviews allowed the researcher to recognise the limit of understanding, as well

as to gain access to the interviewees’ subjective understanding (Seidman, 2006).

Moreover, data were gathered in a relatively short timeframe within the resources

available.Figure 3-9 illustrates the general flow of the interview process used for this

research, which is further explained in the following sub-sections.

Figure 3-9: General flow of the interview process

3.5.1 Identifying and Approaching Participants

The selection of appropriate interviewees is important to ensure the interview

objectives can be achieved. In this research, to obtain diverse perception and insights

regarding the application of IBS in infrastructure projects, the researcher employed

multi-position of construction stakeholders as the interview participants. Imagine

looking into a house from different windows from outside. Particular windows will

reveal a different view and angle of the house. From a certain perspective, you will not

see the kitchen, while from another perspective, you will. Specifically, multiple


viewpoints from different perspectives (the stakeholders) were believed to be

beneficial to providing homogeneous opinions and insights to enhance a one-side view

(Bolger & Wright, 2011).

In this research, the selection of interviewees was based on their industrial

background, experience, and availability within the scheduled interview period. The

details and information about potential respondents were gathered from the official

website of the CIDB, a local university’s website, multiple infrastructure project

developer official websites and the LinkedIn website, which is an online business-

employment-oriented social networking service. In addition to personally approaching

the potential participants, the researcher also sent a letter of “request for nomination”

to several construction companies and relevant institutions to obtain recommendations

regarding participants who could be recruited as interviewees. The snowball technique

was also applied as the interviews progressed. Most of the recommended participants

were proficient and resourceful in the construction industry regarding IBS

implementation and infrastructure projects. The prospective participants were then

approached through email and phone calls. Finally, a total of 20 respondents agreed to

participate in the interviews between April and October 2016.

3.5.2 Sending the Invitations and Setting the Appointments

There are several procedures involved before an interview session can be

undertaken. For this study, once the researcher had compiled the list of prospective

participants, the researcher contacted them, either by email or phone, to approach them

to be research participants, and they were then sent a letter of invitation by email to

provide the research overview and explain the interview objectives. Upon agreeing to

participate, each interviewee was provided with the following documents:

Interview Participant Information Sheet (See Appendix A);

Consent Form for a QUT Research Project (See Appendix B); and

A list of interview questions (See Appendix C)

The list of questions was provided prior to the interview to allow the participants

to prepare themselves for the interview session to better assist the researcher to achieve

the research objectives (Saunders et al., 2009). At the same time, the interview

appointments were set up by agreement of both parties in terms of medium, time, and

location.


3.5.3 Conducting and Concluding the Interviews

Semi-structured interviews were particularly useful in this research for pursuing

in-depth information around the research topic. The semi-structured interview was

equipped with a set of themes and questions about the integration of IBS,

infrastructure, and sustainable development for the preliminary framework validation.

The list of questions for the semi-structured interview was formulated based on the

objectives of the interviews. Questions were open-ended and qualitative in nature to

allow the streaming of insights and impression to expand the interviewees’ thoughts.

The list of questions comprised general questions, with sub-questions where relevant,

as presented in Appendix A. The interviews began with the general questions and then

narrowed to more specific concerns.

At some point, the flow of the interview is led by the interviewees’ insight.

Moreover, the researcher can provide a general context by describing the topic and

related research issues identified in previous research and asking follow-up questions

to obtain rich responses. The interviewees bring the discussion into an area that the

researcher has overlooked but is valuable to be considered (Saunders et al., 2009). This

allows the researcher to capture the views and interpretation from the interviewees,

which is beyond researcher’s viewpoint. The combination of perception and

expectation from the interviewees, together with formulated theoretical basis generates

far-reaching criteria to look into. Subsequently, the research aim and objectives are

refined (if necessary) or remain conclusively established.

One-to-one semi-structured interviews were used in this study. While

conducting group interviews is believed to be more efficient, scheduling all

participants for a particular timeslot can be more challenging (Given, 2016). It was

very challenging for the researcher to manage all 20 interviews within a short time of

period. As most of the participants had their own important role in a project or

company, some refused to be interviewed during working hours. The interviews were

conducted in two different modes: verbal interviews and written interviews. The

employment of each method depends on the convenience of both the researcher and

participants, geographical distance, and the likely duration of the interview.

Researchers must also consider the topic, timing, cost, and logistics, including

participants’ own needs and preferences (Given, 2016).


In this research, verbal interviews were conducted either face-to-face or by

telephone, while written interviews were undertaken via emails. All of the face-to-face

interviews were conducted in Malaysia at the interviewees’ workplace between April

and May 2016. Due to limited time, the unavailability of some participants, and

geographical constraints, phone interviews were undertaken after the researcher

returned to Australia. A number of participants also preferred, and insisted upon,

written communication via email.

Verbal interviews

Face to face interviews are an effective form of engagement that provide prompt

responses via direct communication. The opportunity for the researcher includes a

distinct advantage through understanding gained from the participants’ assumptions

underpinned by body language and facial expression (Rowe & Wright, 2011). In

addition, it is easier for participants to express their own perceptions (Van Djik, 1990),

as well as to clarify any questions or instructions. However, due to time and

geographical limitations, phone interviews may be an appropriate alternative solution.

The approach is similar to face to face interviews, with the exception that facial

expressions cannot be read.

For the verbal interviews in this study, the interview session began with a

briefing about the research and interview objectives. The researcher then verified

whether the interviewee had read the information provided earlier and ensured that he

or she understood the content of the documents. The interviewees signed a consent

form for record-keeping purposes prior to the interview session. All of the interviewees

permitted the researcher to record the conversations. A digital voice recorder was used

for this purpose. The researcher then read out questions based on the list of themes.

There was a list of main questions to be covered, with multiple sub-questions or follow

up questions. However, the researcher omitted some questions or added new questions

depending on the relevancy of the participants’ responses, as long as it was within

research context. The conversations were recorded. Out of consideration for

confidentiality and ethical protection, all voice-recorded interviews were treated

anonymously when transcribed. At the same time, the researcher took appropriate

notes to assist with the information transcription and analysis process afterwards. The

verbal interviews ran individually for approximately an hour.


Written interviews

There were some differences regarding how the written interviews via the online

platform were conducted. The researcher firstly sent out a list of main questions to the

interviewees and waited for their responses. Once the interviewees had replied, the

researcher replied back with the relevant follow-up questions. As with the oral

interview, the follow-up questions for the interviewees were unique, as they depended

on the participants’ initial responses. This process continued until the researcher was

satisfied with the richness of the information gathered. These kinds of interviews are

very time consuming, as the researcher needs to wait for the participants’ responses

before proceeding to the follow-up questions. After three days waiting without any

responses, the researcher reminded the participants via a short messaging system or

short phone call. Even though the nature of this kind of interaction is tedious and

complicated, this written instrument allows the participants to think longer and deeper

about their opinions and views (Van Djik, 1990).

Regardless the mode of interviews, it was expected that the interviewees would

share the benefits and challenges of IBS implementation based on building projects.

As the interviews were constructed in a semi-structured format, the sequence of the

questions was generally inconsistent between the participants, as this depended on how

the responses to the earlier questions led the flow of the topic. As the interviews

progressed, the researcher ensured that the spectrum of the conversation was within

the research scope.

3.6 ANALISING QUALITATIVE DATA

There are generally four main aims of qualitative analysis: exploration,

description, comparison, and testing models, as shown in Table 3-5. In this research,

the data collected from the literature and semi-structured interviews were qualitatively

analysed using QSR international’s NVivo 11 software. This software is very effective

in data management and reduces the issue of handling large quantities of data. It also

provides a simpler coding process for the data, whether in text, images, video, or audio

forms. NVivo also allows the researcher to code particular content multiple times and

offer data matrices. This enables the researcher to identify and recognise the

interrelationships among the codes for more extensive interpretation. The assistance

of the computer software makes the data quicker to access, and easier to explore and


visualise (Creswell, 2007). In brief, NVivo assisted the researcher to break the data

into multiple codes, thus making the qualitative analysis much faster. Figure 3-10

shows the data processing using NVivo.

Table 3-5: Goals of qualitative research (Bernard & Ryan, 2010)

General Aim Type Questions

Exploration What kinds of things are present here?

How are these things related to one another?

Are there natural groups of things here?

Description Case What does a case look like?

Group What does a set of cases look like?

Is a particular kind of thing (A) present or not?

How much of that kind of thing (A) is there?

Cultural What does the culture look like?

Comparison Case How is case X different from case Y?

Group How is a group of Xs different from a group of Ys?

Testing models Case To what degree does a particular case conform to the proposed model?

Group To what degree does a group of cases conform to the proposed model?


Figure 3-10: NVivo 11 interface

The procedures for the interview data processing and analysis were carried out

in the following steps. Firstly, the audio-recorded interviews were fully transcribed

into text documents, which was followed by the coding process. The selection of

coding technique for each study depends on the research construct. There is no definite

method for the best techniques for coding data (Saldaña, 2009). The selected approach

is unique from one set of research to the another (Given, 2016). In this study, all

collated data, including conversation text and relevant articles were coded and sorted

into specific categories. This required predetermined and systematic comprehended

codes to place the data in organised taxonomy (Fellow & Liu, 2008). The researcher

referred to Hahn's (2008a) generic guideline, which uses four common steps of coding,

as shown in Figure 3-11.


Figure 3-11: Qualitative coding level

(Adopted from Hahn, 2008a)

Level 1: Initial coding and open coding

In this research, the researcher firstly established a list of themes before the

coding process was undertaken. Themes were derived from the data (an inductive

approach) or/and from the prior theoretical understanding or literature reviews on the

topic being researched, also known as a priori (or deductive approach) (Bernard &

Ryan, 2010). The researcher initially created themes based on the interview questions,

referred to as initial coding. As the analysis process progressed, new themes were

empirically derived. The act of “code while you read”, also called open coding, allows

for the generation of emergent themes. In NVivo, the researcher creates themes using

the first level node, also known as the parent node.

Level 2: First cycle coding

Coding involves an extensive reading of the dataset to highlight the research

questions being explored. The coding process is iterative, where only after multiple

stages of raw data preparation are they ready to be evaluated, synthesised, and

analysed. In this study, the first cycle coding occurred during the initial step of coding

data. Many coding methods have been listed in the literature (Hahn, 2008a; Saldaña,

2009), as the most appropriate method depends on the research nature and its context.


One coding method alone may be sufficient, or more may be required to capture the

complexity or phenomena of the collected data (Saldaña, 2009).

Provisional coding and holistic coding were adopted for the first cycle coding in

this research. A predetermined set of nodes was established under the themes created.

The provisional nodes list was generated based on the preliminary study of the

literature review, research questions, and the conceptual framework developed in this

study. Holistic coding was deemed appropriate, as the researcher already had a general

idea of what to investigate in the data. Structural coding was then applied to categorise

the nodes. This type of coding is content-based or based on conceptual phrases in the

researched topic. These were created during the literature review and data exploration.

This method was deemed appropriate for the interview transcripts and open-ended

survey (Saldaña, 2009). While this coding process came first, where appropriate, some

of the nodes were revised, modified, deleted, or expanded.

Level 3: Second cycle coding

The main aim for second cycle coding is to develop a sense of categorical,

thematic, conceptual, and/or theoretical organisation from the first cycle coding array

(Saldaña, 2009). This cycle is more challenging, as it requires the skills and abilities

for prioritising, categorising, integrating, and theory building. Similar to the first cycle,

the methods used in this study were mixed-and-matched depending on the research

requirements.

The researcher found that pattern coding was one of the appropriate methods, as

this research was exploratory-based. According to Miles and Huberman (1994),

pattern coding is a technique of categorising the first cycle coding array into fewer

sets, themes, or constructs, which is appropriate for the following applications:

the second cycle coding, after initial coding;

development of major themes from the data;

the search rules, causes, and explanations in the data;

examining social networks and patterns of human relationships;

the formation of theoretical constructs and processes.

In this study, pattern coding helped the researcher to assess the pattern between

nodes by identifying something in common between them. It was also used to develop


statements that described the theoretical constructs of the data. For example, pattern

coding was used to categorise the challenges of IBS implementation, as shown in

Figure 3-12. The 16 items on the left side were initially descriptively coded, the

researcher then used pattern coding to comparatively categorise a collective of

challenges and coded them into a new node.

Figure 3-12: Example of assembly of pattern coding

Multiple level nodes are possible using NVivo. The researcher structured the

hierarchy of the nodes from first and second cycle coding appropriately. An example

of the nodes hierarchy is shown in Figure 3-13. The child nodes represent the

descriptive coding, while the parent nodes were created using the pattern coding

process. The multi-level coding structure provided essential groundwork for the data

representation.


Figure 3-13: Multi-level coding

3.7 DELPHI STUDY

3.7.1 Overview

The Delphi technique is a systematic procedure of structuring a group

communication process between the researcher and a group of identified experts on a

specified topic by assessing the feedback of individual contributions in relation to

information and knowledge (Linstone & Turoff, 2002; Yousuf, 2007). This

communication process involves anonymous interaction where disagreement among

experts exists and iteration is then repeated to the extent that a general agreement

achieved. Experts are managed to be unknown between one another to examine their

own perspectives freely without influence of other factors, such as status and group

pressure, domination of personalities, and lack of self-confidence (Sourani & Sohail,

2015).

A Delphi study is typically conducted through a consecutive round using a series

of questionnaires until the pre-determined total round or pre-determined criteria have

been met, as shown in Figure 3-14. The intermediate feedback of results is analysed

and then used to develop a new questionnaire for the following step. For the following

round, the participants are provided with feedback that involves new information and

expresses the group collective opinion in each round. The feedback process allows and

encourages the selected Delphi participants to reassess their initial judgments about

the information provided in the previous iterations (C.C. Hsu & Sandford, 2007b). A

consecutive round is then repeated until a reliable consensus is achieved.


Figure 3-14: The Delphi process

(adopted from Sourani & Sohail, 2014)

The Delphi method is particularly useful when there is lack of empirical

evidence and historical data (Ameyaw, Hu, Shan, Chan, & Le, 2016; Gupta & Clarke,

1996). It is appropriate for relatively new topics that require a holistic perspective.

However, Delphi is time consuming, as the proceeding rounds can only be executed

once the analysis of the previous outcome has been completed. The process of each

round may last up to several weeks. On the other hand, developing electronic and

information technology provides an opportunity for researchers to employ this

technique more easily. It also provides convenient times and places for the individuals

to be able to participate in a group communication process without a physical presence

(Linstone & Turoff, 2011), making it an inexpensive method to organise and

administer (Gupta & Clarke, 1996). In addition to the pros and cons mentioned above,

Okoli and Pawlowski (2004) compared traditional surveys with the Delphi approach

across several relevant attributes, as shown in Table 3-6.


Table 3-6: Traditional survey versus Delphi study (Adopted from Okoli & Pawlowski, 2004)

Comparative attribute

Traditional survey Delphi Study

Sample representative

Using a statistical sampling technique Virtual meeting or as a group decision technique

Sample size Large enough to detect statistically significant effects in the population

The literature recommends 10–18 experts on a Delphi panel

Individual vs. group response

Average out individuals’ responses to determine the average response for the sample

Average of individual responses is inferior to the averages produced by group decision processes

Reliability By pretesting and by retesting to assure test-retest reliability

Researchers expect respondents to revise their responses.

Construct validity

Careful survey design and pretesting Experts can be asked to validate the researcher’s interpretation and categorisations of the variables

Anonymity Respondents are always anonymous to each other and often anonymous to the researcher

Respondents are always anonymous to each other but never anonymous to the researcher

Non-response issues

Researchers need to investigate the possibility of none-response bias

Non-response is typically very low in Delphi surveys

Attrition effects

Attrition (participant drop-out) is a non-issue for single surveys

Attrition tends to be low in Delphi studies

Richness of data

The richness of data depends on the form and depth of the questions, and on the possibility of follow-up, such as interviews.

Delphi studies inherently provide richer data because of their multiple iterations and their response revision due to feedback.

The Delphi methodology has been used in a range of different settings where

expert knowledge is required to understand a phenomenon in greater depth, thus

obtaining the most reliable consensus of opinions for decision making. In construction

engineering and management research, an area that has regularly utilised the Delphi

method is project planning and design (Ameyaw et al., 2016). The Delphi

methodology has been used in this research context to identify and evaluate project

risks (Adams, 2008; Aritua, Smith, & Bower, 2011; Ke, Wang, Chan, & Cheung,

2011; Seo & Choi, 2008) and to investigate factors in relation to engineering design

and pre-project planning (N. Pan, 2008; C. R. Wu, Lin, & Chen, 2007). In other

studies, Kumaraswamy and Anvuur (2008), Xia and Chan (2012b) and Yeung, Chan

and Chan (2012) used Delphi to resolve procurement-related evaluations in multiple

types of projects. Additionally, in a more recent study, Delphi was also used to identify

and evaluate the effectiveness of various construction methods and technologies,


labour and personnel issues, and information technologies in construction application

and project cost and scheduling (Ameyaw et al., 2016).

Despite the use of the Delphi method in multiple contexts and for different

purposes, the Delphi study used in this research aimed to:

1. Seek the consensus of the previous findings (literature studies and

interviews).

2. Correlate informed judgements regarding an idea that spanned a wide range

of perspectives.

The researcher chose to use the Delphi method to allow for greater participation

of anonymous experts in the construction industry, optimise the researcher’s time and

expense, and for logistic convenience, while still benefiting from subjective judgments

on a collective basis.

3.7.2 Selection of Delphi Participants

The selection of participants is very important in data collection that involves

human interaction. Participants’ judgements can be influenced by several factors, such

as their level of experience, qualifications, and exposure to the research topic (Hasson,

2011). In a Delphi study, the level of expertise and specific characteristics of the

participants are carefully considered because they directly influence the quality of the

outcomes. This study did not utilise a random sampling method because only

responses from experienced and knowledgeable participants was expected to generate

reliable primary data. This research used the Linkedin network to identify potential

panellists. Rowe and Wright (2011) suggested making use of publicly-available

information to improve participants recruitment and retention.

The researcher browsed the Linkedin profile of potential participants who had

experience in infrastructure projects based on the provided information (current and

past project involvement and experience). They were then approached individually by

email or phone to determine their willingness to participate using a one-to-one

recruitment approach. This approach may secure easy agreement from panellist

invitations, which will also strengthen subsequent panellist retention (Rowe & Wright,

2011). At the same time, it maintains the anonymity between the panellists.


In this study, rather than recruiting one specific role of stakeholder (e.g., only

contractors), the researcher searched for and approached various practitioners who

represented different types of firms in the construction industry. In addition,

researchers and academicians with relevant expertise were also approached to add a

range of perspectives. It was hoped that this would increase the likelihood of

diversified views, with individual panellists representing different perspectives (Rowe,

Wright, & Bolger, 1991).

According to C.C. Hsu and Sandford (2007b) there is no exact criterion currently

available in the literature concerning the selection of Delphi participants. Generally,

participants, commonly called “experts”, in a Delphi study are likely to be able to

demonstrate and practice the relevant knowledge within the research topic. Hallowell

and Gambatese (2010) incorporated a flexible point system that requires experts to have

at least four of the following attributes: professional registration, professional

experience, conference presenter, committee participation, peer-reviewed journal

article or book (or book chapter) authorship, faculty member of accredited university,

and advanced academic qualification. However, depending on the research scope,

standard academic qualifications may not add value to the selection of Delphi

participants (Keeney, Hasson, & McKenna, 2011b). Likewise, some research requires

participants that can cover a wide range of interests and disciplinary viewpoints

(Mullen, 2003). Therefore, the researcher may wish to include more specific qualities

or criteria when choosing research participants.

In general, Delphi studies use different numbers of experts. There is no clear

agreement regarding the specific number of participants that should be adopted. As

most Delphi studies in construction engineering and management research incorporate

between eight to 16 participants, Hallowell and Gambatese (2010) suggested that at

least eight participants should be recruited. Sourani and Sohail (2015) recommended

to employ more participants to accommodate the possibility of drop-out of the experts

due to other commitments. Above all, other important criteria to consider are the

participants’ willingness and availability (Keeney et al., 2011b; Sourani & Sohail,

2015).

The selection of the Delphi panellists for this research was based on the

satisfaction of at least one of the following criteria:


i. Possessed at least five years’ experience in the Malaysian construction

industry working with an architectural firm, construction management firm,

engineering firm, infrastructure project developer, or IBS manufacturer

company. They were required to have involvement in infrastructure projects

and be familiar with IBS.

ii. Conducted research in the IBS domain and satisfied at least four of the criteria

outlined by Hallowell and Gambatese (2010) in qualifying as a construction

engineering and management expert from academia.

These criteria have been used as a basis for most industrial surveys in recent

years (Giel & Issa, 2016). Moreover, the participants had to be willing to commit to

multiple rounds of the questionnaires.

3.7.3 Procedures for the Delphi Study

Delphi rounds

The essential element in designing a Delphi study is determining the number of

rounds until the desired consensus is reached. The recommended number of Delphi

rounds has varied among previous studies. For example, Hallowell and Gambatese

(2010) indicated that the number ranged from two to six, while Habibi, Sarafrazi and

Izadyar (2014) reported that past research employed between two and 10 rounds. Most

recently, Ameyaw et al. (2016) demonstrated that Delphi application in construction

engineering and management research employed between two to six rounds, with

almost half reaching consensus after two or three rounds.

There is currently no specific guideline to determine the optimal number of

rounds in Delphi studies (Ameyaw et al., 2016). However, Sourani and Sohail (2015)

emphasised that the determination factor for Delphi rounds should consider both

theoretical and practical factors. Theoretical factors are based on the research aims and

objectives. The two folds of Delphi objectives are to reach consensus by reducing the

response variances and straightaway improve their precision (Hallowell & Gambatese,

2010). On the other hand, practical factors depend on time and risk of participation.

Lack of time, personal issues, and misconceptions about the Delphi procedure have

apparently encouraged refusal of participation in such studies (Hannes et al., 2013).

In a classic Delphi procedure, the initial round employs an open-ended or

unstructured form of questions to seek an open response. This could be called the “idea


generation phase”, which facilitates the exploration of the research subject and

accommodates more representative answers relating to the participants’ thoughts

(Sourani & Sohail, 2015). However, in a modified Delphi, many different mechanisms

have been used for the first round of Delphi in previous studies. Chan, Yung, Lam,

Tam and Cheung (2001); Xia and Chan (2012a); Yeung, Chan, Chan and Li (2007)

practiced the classical Delphi approach by distributing open-qualitative questionnaires

in Round 1 to allow participants to record and list responses. Participants in such

studies are encouraged to provide as many opinions as possible to generate large

amounts of data. It is also important to ensure that the questions are well phrased and

definitive to avoid irrelevant responses (Hasson, Keeney, & McKenna, 2000). On the

other hand, Perera, Rameezdeen, Chileshe and Hosseini (2014) and Zhao et al. (2013)

began their Delphi technique with a well-structured questionnaire and asked the

participants to rate the relevance level of the pre-listed elements or variables. In this

modification, the questionnaire is developed based upon either a comprehensive

literature review, focus group discussion, or one-to-one interview. To some extent, by

using a modified Delphi, fewer than three iterations would be seen as enough (Hasson

& Keeney, 2011). Rather than using the above approach, Rajendran and Gambatese

(2009) structured their first round Delphi questionnaire with open ended questions to

be filled in by the participants and allowed them to rate each their own personal input.

Feedback process

As indicated earlier in Section 3.6, a Delphi study requires iterations of feedback

from the participating experts, and this involves a series of rounds. The data from the

ratings for each round are analysed by producing statistical summaries for each item.

Hasson et al. (2000) suggested using central tendencies (means, medians, and mode)

and levels of dispersion (standard deviation and the inter-quartile range) to provide

participants with information about the collected opinions. However, the selection of

the types of statistical tests undertaken should consider the type of data suitability to

ensure the level of measurement is reliable. For example, standard deviation does not

apply to ordinal or nominal data, thus returning such information to participants in the

following round is misleading (Hasson et al., 2000).

Accordingly, Hallowell and Gambatese (2010) found that simple statistical

summaries are the most common feedback provided in subsequent rounds. This allows

the participants to overview where their response stands among the majority.


Moreover, it is advisable to allow the participants to provide justification for outlying

responses, providing more reliable Delphi results (Hallowell & Gambatese, 2010;

Rowe & Wright, 2011).

Irrespective of the number of rounds required, the strategies employed to

structure the Delphi study requires more attention. How every round is conducted,

whether the instruments are suitably adopted, and how the questions constructed are

imperative.

Measuring consensus

The main emphasis of a Delphi study is to achieve efficient group

communication. Statistical group response is used to represent the group opinion. This

may involve an indication of the opinion variation within the participants (Sourani &

Sohail, 2015).

There are many different types of measurement to decide when to stop the

iteration process. For example, levels of dispersion can be used to measure the level

of consensus among participating experts. On the other hand, consensus is assumed to

have been achieved when a certain percentage of the responses fall within a prescribed

range. In his review, Gracht (2012) outlined a list of consensus measurement options

that have been practiced in previous Delphi studies, which were categorised into two

different approaches: subjective analysis and descriptive analysis or inferential

statistics, as shown in Table 3-7.

Consensus measurement has also been widely used as a sole stopping criterion

(Gracht, 2012). However, it is important to realise that the consistency of responses

between successive rounds is essential to ensure stability in Delphi studies (Keeney,

Hasson, & McKenna, 2011a). It is therefore recommended that Delphi facilitators

include an accompanying stability test for individual opinions and group responses in

successive iterations (Gracht, 2012; C. C. Hsu & Sandford, 2007b).


Table 3-7: Consensus and stability measurement

Type of measurement Criteria

A.

Qu

alit

ativ

e an

alys

is a

nd d

escr

ipti

ve s

tati

stic

s 1. Stipulated number of rounds

The researcher indicates a specific number of iterations based on typical practice due to several situations, such as limited budget, time constraints, or psychological factors.

2. Subjective analysis In the exceptional case of qualitative studies, consensus may be evaluated by content analysis or qualitative data analysis.

3. Certain level of agreement

Suitable for nominal scales or Likert scale types of data. “certain” levels can be based on accepted standards.

4. APMO Cut-off rate (average percent of majority opinions)

𝐴𝑃𝑀𝑂

𝑋 100%,

Provides greater freedom for analysis and interpretation.

5. Mode, mean/median ratings and rankings, standard deviation

Called “measures of central tendency”.

Mode: can be used with all levels of measurement, but is not useful with scales that have many values.

Median: can be used with ranked data (ordinal and interval/ratio), but is not useful for scales with few values.

Mean: can be used for interval/ratio data that are not skewed.

*measures of central tendency are usually analysed in connection with at least one measure of dispersion (e.g., the range, standard deviation, interquartile range, and coefficient of variation).

6. Interquartile range (IQR)

IQR is the measure of dispersion for the median, being equal to the difference between the 75th and 25th percentiles. The more points of scale, the larger the IQRs that can be expected. Rule of thumb: for 10-unit scale, IQR≤2 considered reaching consensus; for 4- or 5-unit scale, IQR≤1 considered reaching consensus.

7. Coefficient of variation (CV)

CV is suitable for the comparison of distributions.

𝐶𝑆𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑑𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛, 𝜎

𝑀𝑒𝑎𝑛, 𝜇

Interpretation rules by English and Keran (1976):

0< CV ≤0.5: Good degree of consensus. No need for additional round.

0.5<CV ≤0.8: Less than satisfactory degree of consensus. Possible need for additional round.

V>0.8: Poor degree of consensus. Definite need for an additional round.

8. Post-group consensus The extent to which individuals individually agree with the final group aggregate, their own final round estimates, or the estimates of other panellists. It is measured after a Delphi process has been completed.


Type of measurement Criteria B

. In

fere

nti

al s

tati

stic

s

9. Chi-square test A non-parametric test to check for the independence of the Delphi rounds from responses obtained in them. It is not actually appropriate since the samples are dependent (as in prior round and subsequent round involves same people).

10. McNemar change test A binomial test to quantify the degree of shift in responses between Delphi rounds, which can be either in a positive or a negative direction.

11. Wilcoxon matched-pairs signed ranks test

Researchers can determine whether a difference between the data of two Delphi rounds has statistical significance.

12. Intra-class correlation coefficient (ICC)

ICCs are designed to assess consistency or conformity between two or more quantitative measurements. They are used primarily to assess the consistency of responses and the levels of agreement among panellists.

13. Kappa statistics Applicable for nominal scale agreement with assumption that the ratings have no natural ordering. A kappa value of 1 represents a perfect agreement among raters. A value of 0 is exactly what would be expected by chance. Negative values indicate agreement less than chance.

14. Spearman’s rank-order correlation coefficient

Spearman’s rank-order correlation coefficient is calculated to reflect the degree of consensus between Round 2 rankings and Round 3 rankings. A high correlation reflects a high degree of consensus.

15. Kendall’s W coefficient of concordance

Is a non-parametric statistic and can be used for assessing agreement among raters for Delphi ranking-type surveys. A coefficient of 0.1 indicates very weak agreement, whereas 0.7 is referred to as strong agreement.

16. t-statistics, F-tests Researchers can use the two samples t-test for the equality of means in order to compare the data of two sub-groups in Delphi study.

The F-test for the equality of more than two means (one-way ANOVA) can, in turn, be used to examine the significant mean differences among more than two (sub-) groups.

Establishing the Agreed Criteria

It should be noted that reaching consensus from the Delphi process does not

necessarily mean that the rating statements are considered to be true or relevant. The

literature review revealed that previous Delphi research utilised many different

indicators to retain the relevant or agreed statements of particular research issues.

Sourani and Sohail (2015) found that common practise used the percentages of

respondents agreeing on certain answers or using standard deviation values. Many

diverging percentages have been used in relation to agreement between respondents.


Chan et al. (2001); Yeung, Chan and Chan (2009) and Yeung et al. (2007) choose 50%

of agreement as an agreed opinion. Similarly, Giel and Issa (2016) eliminated factors

that did not met 50% agreement. Meanwhile, Rayens and Hahn (2000) and Keeney et

al. (2011) respectively suggested at least 60% and 70% of the sample needed to be in

agreement, regardless of how important the statements is. The particular percentage of

agreement to be used could be based on an acceptable standard, such as a simple

majority, two-thirds majority, or absolute majority, as adopted in voting systems

(Gracht, 2012).

On the other hand, Habibi et al. (2014), Lim (2009), Rajendran and Gambatese

(2009), and Xia and Chan (2012a) used mean score as the cut-off point for re-

evaluation in the subsequent round. Habibi et al. (2014) established the cut-off value

based on the number of point scales used in the research, as summarised in Table 3-8.

In contrast, Sourani and Sohail (2015) used multi-indicators and included the mean

value, standard deviation, and percentage of agreement to identify and assign the

relevant criteria.

Table 3-8: Typical cut-off point according to the type of Likert scale (Habibi et al., 2014)

Type of Likert scale Cut-off mean value

9-point 7

7-point 5

5-point 4

3.7.4 Conducting a Delphi Study

A modified Delphi was used in this research. Differing from the traditional

Delphi practices, where the first Delphi round is intended to seek qualitative

information from the panellists, this Delphi study aimed to evaluate the relative

importance or relevance of the thoughts that emerged from the interviews and literature

studies. The structure of the Delphi study applied in this research is summarised in

Figure 3-15. It began with the development of the questionnaire and then proceeded

with two rounds of the Delphi survey. Two rounds of a Delphi survey is practical in

most studies (Mullen, 2003). The following sections explain the process for each round

in detail.


Figure 3-15: The flow of Delphi study procedures.

Development of the Questionnaire

The Delphi study aimed to elicit the panellist’s thoughts regarding stakeholders’

perceptions of IBS in infrastructure projects, and the drivers, challenges, and strategies

that can enhance IBS application towards infrastructure sustainability. A questionnaire

was used as the appropriate instrument to collect the responses from the targeted

panellists.

There were four sections in the questionnaire, with a total of seven questions

posed in the Delphi questionnaire, as shown in Table 3-9. The list of respective items

(factors, drivers, challenges, criteria, strategies, etc.) for each question was developed

based on the interview findings combined with the literature review.


Table 3-9: List of questions in Delphi questionnaire

Sections of the Questionnaire Questions

Section A: Exploration of IBS

Application in Infrastructure

Development

Question 1: To what extent are the following FACTORS

important to be considered to opt for IBS implementation

in infrastructure projects?

Question 2: To what extent do you agree with the

following statement regarding the DRIVERS of IBS in

infrastructure?

Question 3: To what extent do you agree with the

following CHALLENGES of IBS application in

infrastructure projects?

Section B: Identification of IBS

Contribution to Infrastructure

Sustainability

Question 4: To what extent do you agree that the following

ATTRIBUTES of IBS application contribute to

infrastructure sustainability?

Section C: Identification of IBS

Contribution to Infrastructure

Redevelopment

Question 5: To what extent do you think the following

adaptability CRITERIA are important in facilitating

redevelopment of built infrastructure?

Question 6: To what extent do you agree that IBS

application makes easy/facilitates/simplifies the following

changes in built infrastructures?

Section D: IBS Optimisation

Strategies for Infrastructure

Redevelopment

Question 7: To what extent are the following IBS

application STRATEGIES important to promote

infrastructure redevelopment?

Figure 3-16 to Figure 3-21 show the list of items that made up the semi-

structured interviews and the literature for the particular questions and how they were

categorised; however, the categories were left out of the questionnaire. This

questionnaire used a Likert-type scale to measure the agreement of the provided items.

This scale is widely used in many studies as a technique to measure attitudes (Gob,

McCollin, & Ramalhoto, 2007). A traditional 5-categories Likert scale was used to

assess the agreement of the panellists by rating the level of agreement on each item,

with “5” representing “most important” or “most agree” and “1” representing “least

important” or did “not agree at all”.


Figure 3-16: Items for Question 1

Consideration Factors

Project Characteristics

Project size

Type of infrastructure projects

Type of procurement system

Location of project site

Cost of project

Lifespan of project

PolicyRequirement of project developer

Requirement of government policy

Design Requirement

Selection of appropriate IBS system

Specification (e.g., size, dimension) of designed component (or panels)

Application of standardised structural component (or panels)

Application of standardised architectural component (or panels)

Repetitiveness of structural component design

Repetitiveness of architectural component design and features

Industry capacity

Availability of local material

Availability of appropriate technology

Availability of competent manufacturer or supplier

Availability of competent designer

Availability of competent contractor



Drivers

Productivity

Reduce dependency on manpower

Simplify construction activities

Speed‐up on‐site construction activities

Allow simultaneous site preparation and construction works (components or panel production)

Minimise weather‐related delays

Reduce trips of materials transportation

Safety and health

Minimise nuisance (e.g., Noise, dust and traffic disturbance) to site neighborhood

Provide safer working environment

Environmental

Reduce wastage

Reduce energy consumption

Reduce emission

Improve recyclability of components (or panels)

Cost

Optimise material consumption

Reduce construction cost

Reduce life cycle cost

Ensure project cost certainty

Qualify for financial incentives

Increase speed of return of investment

QualityProduce better construction quality

Improve quality control system

Constructability and design

Improve constructability

Offer flexibility

Offer dismantle ability

Increase customization options for special and complex design requirements

Policy and requirement

Client’s requirement

Government policy

Others

Minimise material storage area

Improve competitive capacity

Increase property value



Challenges

Coordination and communication

Poor cooperation between stakeholders

Poor communication between stakeholders

Poor integration for the supply chain

Project deliveryInappropriate procurement practices

Longer lead times for definite project planning and design phase

Design

Inflexible design changes

Highly restrictive construction tolerances

Lack of structural and architectural design integration

Lack of opportunities for standardization and repetition in design

Restrictive for aesthetic and complex design

Limited variability of standard components

Lack of flexibility

ResourcesPoor quality products of components (or panels)

Lack of special equipment or technology

Site constraintRemote project site

Insufficient on-site space for temporary component inventory

Cost

High capital investment

Uneconomic for small-scale project

Abundance of cheap labour

Knowledge and experience

Lack of codes and standard of application

Insufficient knowledge

Lack of experience

Negative perception and sceptism



Attributes

Product Industrialisation

Minimal nuisance to public

Cleaner construction site

Minimal on-site wastage and environmental pollution

Safer and more convenient working environment

Better quality control

Precision in component size and dimension

Option for customisation

Mass-productionOptimisation in material and energy consumption

Cost savings by providing economic of scale

Transportation and assembly technique

Simplified construction activities

Minimal on-site risks

Cost savings on transportation of material

Less carbon emission by reducing of material delivery trips

Recycle and reuse options through dismantle ability

Flexibility to accommodate modification and expansion

Structured planning and standardisation

Minimal errors and mistakes due to component aggregation

Reduced design complexity

Efficient handling and assembly operation

Process integration

Shorter construction timeframe

Effective coordination between stakeholder due to long-term commitment

Substitutability of operational and maintenance arrangement

Availability of spareparts (e.g., panels/connectors/etcs) for future maintenance or modification purpose

Simultaneous design work and components (or panels) production

Low possibility of material or components outage


Figure 3-20: Items for Questions 5 and 6

IBS

Su

pp

ort

for

Infr

astr

uctu

re

Red

evel

opm

ent

Adaptability

Adjustable

Versatile

Refitable

Convertible

Scalable

Moveable

Changeability

Change of space (e.g., layout modification)

Change of performance (e.g., retrofit, refurbish, rehabilitate)

Change of function (e.g., revitalise)

Change of size (e.g. ,expansion, extension)

Change of location (e.g., relocate, deconstruction)



Delphi Round 1

The first round of the Delphi questionnaire was designed to validate the

consolidated list of 128 items identified in the literature and interviews. It was

distributed via QUT Key Survey in March 2017. A total of 15 panellists participated

in this round. The web address link for the questionnaire was sent to the panellists,

together with an invitation letter. The panellists were also provided with the participant

information sheet, which explained the purpose and the guidelines for participation.

The panellists were informed that there would be multiple rounds of questionnaires

and the approximate expected length of time for them to complete the questionnaire.

Strategies

Project Planning

Engage contractor and supplier in the design process and incorporate their concerns

Adopt long-term procurement system which covers post-construction phase

Consider the capabilities to redevelop in the project planning and design

Establish mutual objectives and cooperation among stakeholders

Design Consideration

Use standard size and dimension of the components (or panels)

Reduce the complexity of structural systems

Minimise number of components/panelsMinimise number of fasteners

Minimise different types of materials

Consider high reusable material (Eg; steel)

Use modular wall panel systems

Over-design shear walls

Use non-structural components (or panels) for interior walls

Use common and standard connections

Avoid wet-trade connections

Use lightweight material

Disentangle utilies (Mechanical, electrical and piping) systems from structure

Provide permanent identification of components (or panels) and connections used

Retain all information on the building construction systems, as well as assembly and disassembly procedures

Provide access to all components (or panels) and connection points

Engage with supplier for spare-part supply

Use standard, simple and low-tech construction technology


The risks of participation and confidentiality of the participants were also mentioned

in the sheet.

At the beginning of the survey page, the panellists were briefed with the working

definitions of the terminology used for this research, which included “IBS”,

“infrastructure projects”, and “redevelopment”. This allowed the panellists to respond

to the survey within the research context. Panellists were then requested to indicate

their opinion by choosing the appropriate rating score for each item. In addition, the

panellists were given an opportunity to provide additional items or comments for each

question. This practice allowed for a wider perspective, because there are possibilities

of new thought, as individual experience is unique (Fleming, Boeltzig-brown, & Foley,

2015). A sample of the Round 1 questionnaire is attached as Appendix D.

The panellists were given two weeks to complete the questionnaire. A follow-up

email was then sent to remind all panellists who had not yet completely filled out the

questionnaire within the stipulated time. Text messages were also sent out via the

WhatsApp application. It took three weeks to finish the first round of the Delphi

survey.

The questionnaire responses were then analysed using SPSS. The level of

agreement, mean, and inter-quartile range (IQR) were calculated. The level of

agreement and IQR were used to determine the consensus for each item. Consensus

for this study referred to the interpretation by Diamond et al. (2014) where it is based

on percent agreement and the proportion of panellists who agreed to a specific rating

range.

IQR is a value of the difference between the 75th and 25th percentiles. It was used

to assess the dispersion of panellists’ ratings. The higher the IQR, the more spread out

the data points. Therefore, the smaller the IQR, the more panellists were in agreement,

leading towards reaching consensus. IQR was calculated using the following equation:

𝐼𝑛𝑡𝑒𝑟𝑞𝑢𝑎𝑟𝑡𝑖𝑙𝑒 𝑟𝑎𝑛𝑔𝑒 𝐼𝑄𝑅 𝑄 𝑄

where:

𝑄 𝑇ℎ𝑖𝑟𝑑 𝑞𝑢𝑎𝑟𝑡𝑖𝑙𝑒 𝑚𝑒𝑑𝑖𝑎𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑛 𝑙𝑎𝑟𝑔𝑒𝑠𝑡 𝑒𝑛𝑡𝑟𝑖𝑒𝑠

𝑄 𝐹𝑖𝑟𝑠𝑡 𝑞𝑢𝑎𝑟𝑡𝑖𝑙𝑒 𝑚𝑒𝑑𝑖𝑎𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑛 𝑠𝑚𝑎𝑙𝑙𝑒𝑠𝑡 𝑒𝑛𝑡𝑟𝑖𝑒𝑠


In addition, the level of agreement for each item was calculated to assess the

panellists’ ratings whether leaning towards being relevant or not. The percentage of

agreement was calculated using the following equations:

𝐿𝑒𝑣𝑒𝑙 𝑜𝑓 𝑎𝑔𝑟𝑒𝑒𝑚𝑒𝑛𝑡 %Σ 𝑝𝑎𝑛𝑒𝑙𝑙𝑖𝑠𝑡𝑠 𝑤ℎ𝑜 𝑟𝑎𝑡𝑒 1 𝑎𝑛𝑑 2

𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑛𝑒𝑙𝑙𝑖𝑠𝑡𝑠100%

whereby by scoring “1” and “2”, the panellists considered the items as irrelevant or

not important, and

𝐿𝑒𝑣𝑒𝑙 𝑜𝑓 𝑎𝑔𝑟𝑒𝑒𝑚𝑒𝑛𝑡 %Σ 𝑝𝑎𝑛𝑒𝑙𝑙𝑖𝑠𝑡𝑠 𝑤ℎ𝑜 𝑟𝑎𝑡𝑒 4 𝑎𝑛𝑑 5

𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑛𝑒𝑙𝑙𝑖𝑠𝑡𝑠100%

by scoring “4” and “5”, the panellists agreed that the items were relevant or important.

In this research, two conditions were established to recognise the items achieving

consensus and to identify the appropriate items to be re-evaluated in the Round 2.

Table 3-10 summarises the developed criterion used for the first round Delphi analysis.

Firstly, items with an IQR equal to or less than 1.0 were considered to reflect

consensus. As IQR lacks sensitivity in distinguishing the degree of agreement,

particularly for items with IQR=1.0 (Rayens & Hahn, 2000), the researcher established

a secondary criterion for determining consensus. The researcher used 60% of

agreement to designate consensus as to whether the items were considered relevant or

not. The items that met at least 60% of agreement by the panellist who rated them as

“1” and “2” were eliminated as they were considered not relevant. Meanwhile, if at

least or more than 60% of the panellists rated a particular item as “4” and “5”, it was

considered relevant and retained for further analysis. Items with an IQR more than 1.0,

which fell under category 3, were included in the round 2 Delphi questionnaire because

there was significant variability in the distribution of responses among the panellists.


Table 3-10: Decision criteria recognising the relevant item

Category of rated items

Criterion Results

Required action IQR value

Percentage of agreement

Reaching Consensus?

Consider relevant?

Category 1 ≤ 1.0 ≥ 60% of participants rate for 4 & 5

Yes Yes Retained as agreed/ relevant item

Category 2 ≤ 1.0 ≥ 60% of participants rate for 1 & 2

Yes No Eliminated

Category 3 >1.0 - Not yet Not yet Consider to be re-rated in Round 2

Delphi Round 2

The Round 2 Delphi questionnaire was designed based on the results of the first

round Delphi, which gave the panellists another opportunity to reconsider their

answers based on the anonymous Round 1 responses for the remaining 49 items. The

consolidated results of Round 1 Delphi, which contained mean and median ratings

awarded for each of the remaining items, were disclosed to the panellists to provide

controlled feedback. A sample of the second round Delphi questionnaire is attached as

Appendix E.

The Round 2 questionnaire was distributed via Key Survey in May 2017. The

panellists were given two weeks to complete the questionnaire. Two email reminders

were then sent fortnightly for those who had not responded within the stipulated time.

This round took longer than the first round. After six weeks, it was assumed that two

of the panellists had withdrawn their participation from the survey due to their heavy

workload. Finally, a total of 13 panellists completed the questionnaire for Round 2

over a period of five weeks.

Similar to Round 1, the questionnaire responses were analysed using SPSS. The

level of agreement and inter-quartile range (IQR) were calculated to recognise the

consensus of each item. All relevant items that complied with Criteria 1 (see Table

3-10) from both Delphi rounds were then compiled. The mean value for each item was

then calculated. A mean rating of 4.0 and above was implemented to determine the

high ratings and considered significant.


3.8 DATA TRIANGULATION

Triangulation refers to the practice of combining multiple methods of research

(Oleinik, 2011). In qualitative research, triangulation has been viewed as a strategy to

provide validity through the convergence of information from different methods,

theories, sources of data, or investigators (Carter, Bryant-Lukosius, DiCenso, Blythe,

& Neville, 2014). According to Denzin (1978), no single method ever adequately

solves the problem of rival causal factors, as each method reveals different aspects of

empirical reality. The integration of multiple methods and cross-verification is more

reliable than relying on a single source of evidence.

This study used triangulation in the data collection method by using a review of

the literature, interviews, and the Delphi study. This research involved both qualitative

and quantitative data, and by combining multiple types of data it could overcome the

weaknesses or intrinsic biases and the problems that come from using a single method.

The triangulation of qualitative and quantitative data from multiple approach in this

study is illustrated in Figure 3-22. The results of the individual techniques were

triangulated to yield synergy. This allowed the researcher to integrate and justify what

the theory said and what previous research had found in relation to the real perspectives

of participants from the local industry, specifically in the Malaysian context; thus,

providing richer insight and a clearer understanding to assist in making inferences

towards objectives and in drawing conclusions.

Figure 3-22: Triangulation of quantitative and qualitative data

(Adopted from Fellow & Liu, 2008)


3.9 RESEARCH RIGOUR AND VALIDITY

The essential element of conducting research is to demonstrate research rigour

and validity. According to Richards and Morse (2002), this begins with the researcher

as the main instrument. The researcher should be well-equipped with research skills

and literature knowledge about the subject to be researched. Research rigour needs to

be upheld and maintained during the whole research process (Meadows & Morse,

2001). However, the rigor of qualitative and quantitative research is construed

differently (Given, 2016). Quantitative research is not viewed as more rigorous than

qualitative research, or vice versa.

3.9.1 Establishing Rigour in Qualitative Research

Qualitative researchers describe the nature of rigour in their research using their

own language. The terms “validity” and “reliability” are arguable in qualitative

research (Richards & Morse, 2002). Many other criteria have been used by previous

researchers to describe the attributes of rigor in qualitative studies, as described below:

Credibility

Credibility is equivalent to internal validity in quantitative research, which

denotes the ability to represent the truth value of a study. Appleton (1995) claimed that

the credibility of a qualitative study is deemed if it reveals accurate descriptions of

individual experiences. Thus, other people who shared a similar experience will

recognise it (Thomas & Magilvy, 2011). Shenton (2004) also suggested that qualitative

research is credible when the investigator can demonstrate a true picture of the

phenomenon under study. He stated that it is important to provide a detailed

description of the research area, the actual situations being investigated, and the

context surrounding them. In this research, the researcher provided the scope of study,

as presented in Section 1.6, to ensure the research topic and scope were appropriately

identified and described.

Maxwell (1992) was also concerned with the accuracy of the researcher

reporting the interviews due to miss-hearing, miss-transcribing, or misremembering

participants’ words. Thus, audio recordings were used in this research, which allowed

the conversations to be replayed multiple times to provide more accurate transcription.

On the other hand, Guba and Lincoln (1994) also suggested that internal validity can

be achieved by establishing a controlled procedural research process. Therefore, in this


study, the researcher addressed the procedures employed for collecting and analysing

qualitative data (as described in Section 3.5 and 3.6). Moreover, it is useful to employ

the concept of triangulation to ensure the data collected in a study are credible (Given,

2016). Triangulation of data provides a complete understanding of a phenomenon

being studied, rather than relying on a single source in addition to increasing

confidence in the results (Cutcliffe & McKenna, 1999). Rather than depending on one

approach, the development of the framework in this study was generated from a

triangulation of the findings from the literature, interviews, and Delphi study.

Transferability

Known as external validity in a qualitative research nature, transferability refers

to the degree to which the findings can be applied to other contexts and settings

(Thomas & Magilvy, 2011). This concept does not generally apply to qualitative

research, as the inquiry is subjective, interpretive, and bounded by a specific time and

context. However, to design transferable qualitative projects, the nature and size of the

sample, as well as particular characteristics of the social and cultural contexts must be

carefully considered (Given, 2016).

This research provides sufficient detail relating to the research context, as

described in Section 1.6. However, it should be noted that for qualitative research, only

the context of research is transferable, not inferences (Shenton, 2004). On the other

hand, Richards and Morse (2002) claimed that the aspect of trustworthiness is more

relevant for a qualitative study. As such, the term “applicability” is used more widely

to establish rigor in qualitative results, rather than arguing transferability. Shenton

(2004) believed that providing the following information is essential before attempting

its applicability, and this includes:

• The number of organisations that took part in the study and where they were

based.

• Any restrictions on the type of people who contributed data.

• The number of participants involved in the fieldwork.

• The data collection methods that were employed.

• The number and length of the data collection sessions.

• The period over which the data was collected.


Most of the above information was reported in the relevant chapter for this

research. Only with adequate information can readers make a judgement about the

transferability of the information; however, this is neither simple nor straightforward

(Given, 2016). After all, the application of the findings to different natures and

populations is conceivable by abstraction and decontextualisation of emerging

concepts and theories (Morse, 2015).

Dependability

Dependability, also known as reliability in the quantitative inquiry, is broadly

described as the degree to which the findings would be repeated if conducted with the

same participants or in similar settings (Given, 2016). In other words, it is the ability

to reproduce identical results if the study were to be repeated. It is important to realise

that the coding process used during data analysis plays an important role to in ensuring

research reliability (Morse, 2015). It is desirable to pre-establish a coding system and

check for inter-rater reliability (if involving multiple coders) to ensure that the meaning

of the analysis between the coders is consistent.

In this research, the researcher adopted the coding strategy presented by Hahn

(2008a), as reported in Section 3.6. Other strategies used to establish dependability

include the provision of the extensive methodological processes (Thomas & Magilvy,

2011), as outlined in the research design and methods section (Section 3.53.6 and 3.7).

However, the process of replication for qualitative studies can, to a certain extent,

destroy the induction process in qualitative analysis (Morse, 2015).

Confirmability

Guba and Lincoln (1989) used the term “confirmability” instead of

“consistency” in establishing the trustworthiness of qualitative research. This occurs

once credibility, transferability, and dependability have been established (Thomas &

Magilvy, 2011). Flick (2007) indicated that reliable studies exhibit data transparency,

which offers recognisability between interviewee statements and researcher

interpretation.

In this study, the quotations of the interviewees’ statements are provided in

italics (see Chapter 4:). Quoting the interviewees statements along with the

researcher’s interpretation provides confirmability that the findings are grounded in

the interviewees’ data, not solely the researcher’s point of view. To ensure that the


interviewees’ perceptions were not influenced by the researcher’s presumption or

unconscious bias, the researcher attempted to avoid any potential biases by asking

neutral questions that did not assume a particular outcome (Given, 2016).

3.9.2 Methodological Rigour in a Delphi Study

Delphi techniques have been modified over the years to enhance the

methodological rigour. Keeney (2010) identified 10 different types of Delphi designs:

classical, modified, decision, policy, real-time, e-Delphi, technological, online,

argument, and disaggregative Delphi. The designs differ based on (but are not limited

to) the study aims, target participants, administration conducts, the number of rounds,

and the execution of each round. Variance also exists within each type of Delphi design

(Hasson & Keeney, 2011).

The foundation of a good research is establishing methodological rigour. This

refers to the responsibility of the researcher to ensure that the research procedures will

produce solid results. To ensure the methodological rigour of a Delphi study, it is

important to consider the applicability of the Delphi method to a specific problem, the

selection of respondents and their expertise, the design and the administration of the

questionnaires, the approach of communicating feedback, and the relevance of

consensus measurement (Jillson, 1975). Correspondingly, the most critical challenges

to achieving methodological rigour in a Delphi study are the determination of

consensus and the number of rounds (Hasson & Keeney, 2011). As each study’s

design, sample, and consensus process is unique, the establishment of appropriate

measurement in each Delphi test is debatable in the literature. The justification for the

appropriate selection of approaches while conducting a Delphi study in this research

was described in Section 3.7.

Day and Bobeva (2005) suggested that incorporating both qualitative and

quantitative perspectives could enhance the quality of a Delphi study. The qualitative

data from the interviews and literature review were used as a basis for the development

of the Delphi questionnaire in this study. At the end of each Delphi round, the ratings

were analysed quantitatively using statistical measurement to review the consensus.

Thus, both approaches were applied in this study.


Minimise bias

Hasson and Keeney (2011) claimed that the avoidance of group bias and group

thinking enhances the reliability of the results. Therefore, the success of gathering data

from a group of experts depends on the unbiased judgement among them. Likewise,

as adopted in this study, the element of anonymity reduces the potential for dominance.

In this research, the panellists responded to the Delphi questionnaire individually.

Their judgements were not influenced by fear of losing credibility. This is consistent

with Hallowell (2008), who also recommended other strategic controls to minimise

any bias, such as randomising questions in the survey, providing reasons in controlled

feedback, conducting multiple rounds of surveys, reporting median values, and

maintaining anonymity.

Bias may also occur during the data analysis. The selection of items to be carried

forward for subsequent rounds of Delphi study requires careful consideration (Hasson

et al., 2000). Therefore, a standard procedure for selecting or eliminating items was

properly established for the Delphi study in this research, as presented in Section 3.7.4.

Validity

Hasson and Keeney (2011) discussed the validity of a Delphi study from three

aspects: content, construct, and criterion-related validity. For content validity, a group

of experts provides confirmative reliable judgement instead of a single-person

decision. Moreover, Delphi allows participants to review the relevancy of collective

items, which are generated individually at the initial phase, and in the subsequent

rounds. Likewise, in the second round of Delphi in this research, the consolidated

results of the Round 1 Delphi, including the mean and median ratings, were disclosed

to the panellists to provide controlled feedback. Okoli and Pawlowski (2004) and

Schmidt (1997) also supported this practice for verification purposes. This action

validates the researcher’s interpretations, thus indirectly enhancing the construct

validity. On the other hand, in order to achieve content validity, C. C. Hsu and

Sandford (2007a) recommended a modified Delphi with close-ended survey after the

first round. Even though the structured Delphi questionnaire in this research was pre-

established, the panellists still had the opportunity to contribute new supplementary

ideas whenever they found it relevant for each question.

Another key point is that criterion-related validity in a Delphi study requires two

folds of validation techniques: concurrent validity and predictive validity (Hasson &


Keeney, 2011). The former is measured by comparing the outcome with another

validated study that has been conducted at the same time, while predictive validity

refers to the accuracy measurement of the Delphi. Correspondingly, the successive

rounds of the Delphi survey presumably contribute to concurrent validity, as similar

panellists have rated the items in multiple rounds (Hasson & Keeney, 2011).

Meanwhile, the predictive validity requires comparable measurement to validate the

accuracy of the findings. This can be undertaken using a case study (Lim, 2009; Xia

& Chan, 2012b; Yeung et al., 2009), literature review (Yeung et al., 2007), or focus

group (de Loe, 1995). This is why purposive sampling of panellists’ nominations is

important. Thus, only potential participants who had sufficient experience and

knowledge of the research topic were approached for this research. A list of criteria

for selecting the Delphi panellist was established and presented in Section 3.7.2.

3.10 ETHICAL ISSUES

This research was approved by the QUT Research Ethics Committee (UHREC)

and considered to be a low-risk project. The ethics approval number for this research

is 1600000215.

3.10.1 Risk

This research was considered low risk. The organisations and project

information details were anonymous. The information collected was not personal in

nature. All identity information was de-identified and confidentiality was protected for

the project organisations involved. There were no physical or emotional risks/harm for

any participants in the interviews. Participation was on a voluntary basis and all

participants had the option to cease their participation. The potential risks are

summarised in Table 3-11.


Table 3-11: Potential risks

Risk Description

1. Intruding on the participants’ time (Likelihood: low)

The interview session exceeds the scheduled duration.

The participants do not appear at the scheduled time.

2. Participant cannot commit to the research due to his/her tight schedule (Likelihood: low)

Drop-off in participation.

Opinion, perception, and thoughts will be limited.

3. Miss-statement or misinterpretation

(Likelihood: very low) Limitations in experience and knowledge of

the researcher could lead to misunderstanding.

4. Reputational risks, as individuals or/and organisations in the field or institution (Likelihood: low)

Disagreements or conflicts between participants.

5. Travel risk

(Likelihood: low) Physical injury or/and psychological harm.

6. Ergonomic discomfort, working body postures during work on desk/with computer/at workstation

(Likelihood: medium)

Backache

Muscle pain

3.11 SUMMARY

Research methodology contains the technical practices of research strategies as

a medium to answer the research questions, thus achieving the research aims and

objectives. The strategic methods and techniques to be adopted are dependent on the

nature of the research questions. For this study, the researcher carried out a systematic

literature review to initially explore the issues and topic of the research. This enabled

the researcher to develop the preliminary conceptual framework as a foundation of this

research. The researcher utilised multi-method qualitative data collection strategies,

which included an extensive literature review, semi-structured interviews, and a

Delphi study, to gather the relevant information to reflect the research questions.

Ethical clearance was undertaken prior to commencing the data collection activities.

As the intent of this research is to develop new insights on a particular subject, the

collective data were analysed qualitatively and quantitatively to provide multiple

perceptions in order to formulate a valid and reliable outcome.

Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 127

Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects

4.1 INTRODUCTION

This chapter reports the results of the semi-structured interviews, undertaken

using purposeful sampling with researchers and industrial practitioners. The

interviews were conducted with the objective to: (1) explore perceptions and

understanding about IBS application and infrastructure projects; (2) explore the

applicability of IBS in infrastructure projects by examining the project characteristics;

(3) discover the strategies of IBS implementation in infrastructure projects, and (4)

discover the sustainability potential through IBS application in delivering sustainable

infrastructure. In addition, at the beginning of the interviews, the researcher aimed to

validate the relevance of the established preliminary conceptual research framework.

The information extracted from the interviews provide a foundation for the subsequent

Delphi study. This chapter explains the data collection process used for the semi-

structured interviews, including the process used for participant selection and the

interview format and structure. This is followed by the data analysis results and

relevant findings. Finally, the last section summarises the overall outcome of the

interviews.

4.2 PROFILE OF INTERVIEWEES

The selection of interviewees was based on their qualifications and experience

in IBS implementation and/or infrastructure projects. It was important to ensure the

participants were able to provide valuable information based on their experiences and

knowledge. Most of the participants were from the private sector, with the exception

of three, who were worked for a government agency. The identity of the interviewees

remained anonymous. The demographic details of the respondents are provided in

Table 4-1.

Twenty individuals were recruited, representing diverse professional roles,

organisation types, and levels of experience (see Table 4-1). Therefore, the interview

128 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects

findings covered wide-ranging perspectives and provided strong data-input validity

regarding the research topic. These interviewees offered a holistic stakeholder and

industry perceptions of the sustainability of the IBS application in general, and

infrastructure projects specifically. Furthermore, the involvement of academicians and

researchers provided a wealth of theoretical knowledge into the actual practices of IBS

implementation. This diversification allowed for the research topic to be examined

from the perspective of the experts and obtain the reasons behind particular

perspectives.

Table 4-1: Interviewees demographic information

ID Interviewee Position Stakeholder

Type

Years of industrial experience

Years of IBS

experience

Interview Type

P1 Director Manufacturer/

Contractor 21~30 5~10 Face-to-face

P2 IBS Specialist /

Consultant Manufacturer/

Consultant 11~20 11~20 Face-to-face

P3 Consulting Engineer/

IBS Trainer/ Competent Project Manager

CM Consulting/ Government

Agency/ Academic Institution

>30 >30 Face-to-face

P4 Lead Planning Engineer Contractor 11~20 5~10 Phone/Skype

P5 Principal Consultant Contractor >30 <5 Face-to-face

P6 Resident Architect Consultant 11~20 11~20 Email/Online

P7 Resident Architect Consultant 21~30 11~20 Email/Online

P8 Senior Design Engineer Manufacturer 5~10 5~10 Phone/Skype

P9 Senior IBS Engineer Manufacturer 11~20 11~20 Email/Online

P10 Head of Innovation and

Development/ Researcher

Manufacturer 11~20 11~20 Face-to-face

P11 Director Architecture Consultant

21~30 11~20 Face-to-face

P12 Project Engineer Consultant 5~10 5~10 Email/Online

P13 Professor/ Senior

Director

Research/ Academic Institution


P14 Senior Manager Authority/

Government Agency


P15 IBS Specialist Consultant 5~10 5~10 Face-to-face

P16 Senior Manager Developer 11~20 5~10 Phone/Skype

P17 Director Manufacturer/

Consultant 21~30 21~30 Face-to-face

P18 Construction Manager Consultant 21~30 5~10 Phone/Skype

P19 Director / Researcher Research Institution >30 21~30 Face-to-face

P20 Director / IBS

Consultant/ Trainer Consultant 11~20 11~20 Email/Online


4.3 INTERVIEW RESULTS

This section presents the findings, which were extracted based on the topics

related to the research questions. At various points, participants did not answer the

specific question, as they sometimes expressed their opinion about other interview

questions while discussing a particular topic. Thus, the findings are not presented

according to the list of interview questions, but are instead organised by topic in the

following sections.

4.3.1 Perception of IBS Implementation in Infrastructure Projects.

General understanding of industrialised building system

The researcher believed it was important to firstly investigate the participants’

basic understanding with regards to the concept of IBS application in construction

projects. Thus, at the beginning of the interview session, the designed questions

allowed the participants to describe what they thought IBS was. This was important to

observe their awareness regarding to what extent IBS is applied in the construction

industry as a whole. The 100 most frequent words used by the participants when they

described IBS were compiled and are illustrated in Figure 4-1.

Figure 4-1: Word cloud of 100 most frequent words explaining IBS


The interviews revealed that understanding of IBS among the participants was

not universal. Some of the participants described IBS in the simplest terms, while

others explained the term comprehensively. Several elements emerged while

describing IBS, these were: construction innovation; production industrialisation;

assembling or installation technique as construction method; and structured planning,

integration, and standardisation in construction processes. In addition, IBS was also

described in multiple terminologies, as shown in Table 4-2.

Table 4-2: Interpretation of IBS definition by the interviewees

Definition classification Quotation by the interviewees

Associate terminology Prefabricated system/construction (P3, P7, P14, P18), precast (P1, P4, P8, P9, P11, P14, P18), modular system (P13, P14), off-site construction (P14), 3D construction (P17), prebuilt (P17)

Construction innovation “…an evolution in the construction industry.” (P1)

“...modern method of construction” (P14)

“…towards modern construction components.” (P18)

Product industrialisation Components are produced in the factory then sent to the site for installation (P2, P3, P4, P7, P10, P11, P12, P14)

Building components are cast under a controlled environment, either on-site or off-site. (P8, P11, P15)

“...industrialising the process by manufacturing the same product in the factory.”(P1) “…manufacture the parts, each part being uniquely labelled and installed on site.”(P7)

“...structural components are produced and tested in the factory, quality guaranteed…” (P12)

“ready-made product.” (P18)

“tailor-made product.” (P13)

Assembling or installation technique of construction method

“Building here is not meant by a physical structure actually. Building means construction. Constructing.” (P1)

“IBS is a system whereby a component of [a] structure/building is manufactured elsewhere, be it in a factory/casting yard and transported to [the] site for assembly work with [a] certain assembly system.” (P6)

“IBS is a system where we construct the building/project using precast/prefabricated building components.” (P9)

“It is about industrialising the process rather than product.” (P10)

“[A] building system that involves [the] installation process, and should be mechanised…” (P11)

“It is more about launching [an] erection or installation.” (P19)


Based on the summary above, the majority of the interviewees associated IBS

with the process of industrialising the construction components under a controlled

environment, with transportation of the products then taking over before installation

takes place on the construction site. However, there was some misconception about

the term by some participants where they restricted the IBS application only to

building construction. This was probably due to the literal translation of the word

“building” being interpreted in two different meanings in the Malay language, either

“building” is a physical structure as a noun, or “building” is an act of construction as

a verb. Revisiting the CIDB definition of IBS; the latter meaning is the substantial

meaning. In other words, IBS is a construction system that involves component

production, delivery, and installation. It is important to realise that, as stated by (P9),

“most of the design or system requires connection between precast and also in-situ

concrete to become monolithic or [a] complete structure”. Figure 4-2 illustrates IBS

execution based on the compilation of the interviewees’ thoughts.

Figure 4-2: Compilation of IBS thoughts of interviewees.

Drivers and benefits of IBS implementation

The interviewees believed that IBS would provide desirable benefits to

construction project development and provide significant contributions to the project

objectives: quality, cost, and time. As reported in this section, the interviews yielded

some findings about the benefits and these correspondingly become the drivers of IBS

implementation in current construction projects in Malaysia. A participant

optimistically mentioned:


“I always believe (sic), sooner or later, Malaysia will go towards fully-

IBS construction. There are a lot of factors. The factor of foreign

workers, factor of control of quality, factor of the environment, factor of

safety.” [P1]

A list of relevant terms and key points expressed by the interviewees that referred

to IBS advantages are provided in Table 4-3. The drivers were divided into several

concerns, including time efficiency, quality, productivity, safety, environmental

performance, technical, and regulation requirements.

Table 4-3: A summary of IBS advantages.

Key concerns IBS advantages mentioned by the interviewees

Time Speedy (P2, P3, P11), faster (P2, P13, P20), save time (P4), time reduced (P6), shorten time (P7, P12, P16), expedite (P16, P19)

Cost Save cost (P4, P7, P18), reduce cost (P6, P8), cost effective (P11)

Quality Quality controlled (P1, P13), More durable (P2), high quality (P3, P20), precision (P6), guaranteed quality (P12), better quality (P16, P18)

Productivity Reduce the number of workers (P2), reduce human involvement (P11), reduce manpower (P12), use skilled workers (P16), dependable on machinery (P18), simplify (P15)

Safety & Health Neat and tidy (P1), cleaner site (P2, P13, P19), less wastage lying on site area (P4), assure/improve safety (P1, P7), improve site cleanliness (P12), less wastage (P4, P13, P17), minimise traffic disruption (P7)

Policy & Regulations

Requirement by authority (P11), client requirement (P4)

The interviews revealed that participants believed that IBS would contribute to

time efficiency. Project duration is one of the most concerning factors for project

stakeholders in the construction market (Eriksson et al., 2014; Larsson et al., 2014).

The majority of the interviewees agreed that IBS helps to complete the project faster.

IBS allows some of the construction activities to be carried out concurrently.

Interviewee P2 said:

“…you can cast off-site while you are doing the work on the site. So, let

say at the time the piling [is] in progress, the casting activities are

already finished.” [P2]


This shows that the sequence of construction activities that involve IBS is no

longer linear. Production of structural elements could be undertaken parallel to other

on-site construction activities. This situation would logically reduce project duration.

With regards to this, one of the project consultants concluded that:

“…time [will] reduce, which will greatly save the cost of the

development.” [P16]

Although the above statement is very generic, these interviews revealed that the

factors that related to cost savings were based on consumption of material and human

resources. The assured quality of pre-made components and the productivity efficiency

of construction activities then leads the drive towards IBS application.

Quality is one of the performance measurements for project development. In this

situation, the quality of IBS components plays an essential aspect. Many participants

agreed that component production under a controlled environment promises higher

quality products. Some participants stated:

“The durability is guaranteed because the products which [are]

produced by the supplier have been through a process of quality control

and quality assurance to ensure internal and external quality.” [P12]

“…quality wise [it] is much more, and we can control the product

quality because we can control the machine.” [P19]

“The components are produced at the factory. It should achieve the

specified [specifications] as they expected.” [P14]

Additionally, P2 and P3 also claimed that a higher quality of components

provides a longer lifespan. Thus, minimal maintenance is required.

In terms of productivity, most of the participants highlighted that conventional

construction involves an abundance of cheap foreign labour. As dependency on foreign

workers has been a critical issue in Malaysia, the minimisation of on-site labour and

employment of skilled workers for IBS application would more or less overcome this

issue. One of the participants stressed:

“…when [it] comes to a time where labour is no longer cheap and

abundant, so this would be a time where the use of IBS would be

critical.” [P19]


On the other hand, IBS application eliminates some on-site activities, such as

concreting and plastering (P1), as well as eliminating irrelevant construction material

from the use of formwork (P2) and scaffolding (P8). This also provides a cleaner site

area with minimal material wastage, therefore keeping the working environment safer

(P1, P2, P7, P12, P17 and P19). Moreover, pollution caused by spreading dust and

vibration noise from concreting activities can also be avoided (P1 and P11). As quoted

by one of the participants:

“…remove (sic) all [of] these kinds of unnecessary things could resolve

[the] 3Ds of [the] construction label, which is (sic) dirty, difficult, and

dangerous” [P17]

While in the technical aspect, design requirements and project location demand

the application of IBS. One project consultant said:

“Engineers prefer to do the simple and easy design, as long as the

structure [is] safe. But for the architect, they have their own design, so

we have to go for the alternative.” [P18]

The above situation occurs when a special architectural design or special shape

is required for a specific structure. The interviewees believed that a steel structure

could be a better option for a very long span concrete structure (P13, P16, and P18).

Another point made was that for projects that are located in an urban area, especially

those that affect traffic conditions, IBS application is the best option (P11). Instead of

a traditional build-up, erection and installation of pre-cast components makes the

construction process faster, while minimising traffic disruption (P7).

Overall, it was believed that IBS could become a compulsory requirement in

some construction projects, either by authority (P11) or by the project developer

themselves (P4). Government building projects are subjected to utilise at least 70% of

IBS while 50% for the private sectors. This regulation is in conjunction with a

government effort to promote IBS practice among project stakeholders.

Challenges of IBS Application in Infrastructure Projects

In addition to the benefits captured by the researcher during the interviews, the

interviewees also put forward some challenges and limitations related to IBS

application. The participants believed that these challenges were not permanent and


could be resolved over time. It is therefore important for the industry to be aware of

these challenges and how to manage them.

This section reports the challenges and limitations of IBS application as reported

by the interviewees, and then discusses the interview data that provides support for

these findings. The corresponding literature evidence is provided in Table 4-4. The

participants were not questioned directly regarding the challenges; instead, the

researcher determined this information from participant’s responses to other questions.

The challenges were grouped into three main categories: cost, technical, and the

stakeholders’ awareness and competency. The findings related to each of the

categories are discussed below:

Table 4-4: A summary of challenges of IBS applications.

Key concerns Challenges mentioned by the interviewees

Costs

High cost (P4, P8, P11, P15 and P17)

High capital investment (P1, P3, P4, P5, P11)

Uneconomical for small scale (P2, P3, P16, P17)

Limited local resource (P18)

Availability cheap labour (P15, P19)

Technical

Longer lead time (P6)

Inflexible design changes (P2, P14, P18)

Inappropriate for the aesthetic of the architectural design (P1, P2, P8, P12, P16, P19)

Limited variability of standardised components (P12, P19)

Lack of standard/specification of IBS implementation (P8, P11, P15)

Delivery or transportation difficulties (P2, P8, P11, P14, P17, P18)

Limited on-site storage space (P2, P18)

Stakeholders’ Awareness and Competency

Limited competent contractor (P3, P15)

Limited competent consultant (P15)

Limited competent manufacturer (P15)

Conflict between stakeholders (P1, P2, P8)

Resistant to change (P1)

The majority of the interviewees raised cost as the main concern of IBS

implementation. Even though some of the participants agreed that cost savings might

be achieved, some stated that IBS application is expensive (P4, P8, P11, P15, and P17).


IBS involves huge expenditure for the initial investment for upfront payments by the

contractor to the supplier (P1) and buying or renting costs for adoption of a reusable

formwork system (P4). This explains why some participants (P2, P3, P16, and P17)

claimed that IBS is uneconomical for small-scale projects. Moreover, a limited local

resource for certain materials, such as steel products, contributes to the higher cost of

IBS application (P18). However, some participants believed that the availability of

cheap foreign labour allows conventional practices to remain the better option (P15

and P19).

The interviews also revealed that there are many technical aspects impeding IBS

implementation, particularly in infrastructure construction projects. During the

interviews, the participants referred to design issues as one IBS application challenge;

for example, a longer lead time is required for the design stage (P6). The designers

have to work very carefully, as every component is critical to building up a complete

whole unit structure. As IBS components are pre-fabricated, this does not allow for

prompt design changes after the components are produced. Some of the participants

found this to be a disadvantage, especially if unexpected problems occurred during the

installation or construction phase. For example:

“…during the installation, defect or any deficiency could happen.”

[P14]

“The new components need to be redesign based on problems [that]

happen on-site.” [P18]

Design issues could be more tedious if the architectural design is too futuristic

with a unique or fancy pattern (P1, P2, P8, P12, P16, and P19), especially with the

limited variability of standardised components available in the market (P12 and P19).

This usually creates conflict between the engineer and the architect. Interviewee P2,

who was representing engineers, expressed that:

“They (referring to architects) prefer to produce something that looks

fancy or futuristic. However, they actually don't bother about the

construction method… The aesthetical value is more important for their

design stand” [P2]

However, there is a significant need for mutual understanding between both

parties to resolve such conflicts. Unfortunately, there are no collaborative standards


and specifications for IBS implementation for practitioner reference (P8, P11, and

P15).

The other technical difficulties in implementing IBS relate to the delivery and

transportation of the prefabricated components. Massive structures require many

delivery trips, thus contributing to a huge investment in transportation costs (P2, P8,

P11, P14, and P18). Additionally, for a project located in an urban area or residing

close to a nearby traffic route, the delivery scheduling is critical, as there is very limited

space for temporary component storage (P18). Meanwhile, if the project is situated in

a remote area, the cost of transportation becomes higher and it may not be worthwhile

to apply IBS (P17).

Due to a limited number of competent contractors, consultants, and

manufacturers with relevant experience and knowledge, the interviewees claimed that

IBS application is challenging (P3 and P15). One interviewee expressed that:

“…as long as you have the knowledge and understand how to apply IBS,

then it should be ok. When you don’t have them, then you have a lot of

limitation.” [P15]

Based on experiences shared by P2, there is a possibility for a contractor to

change their minds and not proceed with IBS application in the middle of project

execution. P2 provided two different cases (referred as case 1 and case 2) as examples.

In case 1, the incapability of suppliers to produce IBS components on schedule caused

the project to overrun due to late delivery. In case 2, late payment by the contractor to

the supplier caused the supplier to refuse to proceed to delivery. The contractor was

not able to manage the time overrun and disagreement, and as a result, the contractor

decided to complete construction conventionally.

The interviews showed that, although most interviewees recognised the

application of IBS in general, there was still a lack of understanding about the complete

principle of IBS. Typical understanding of IBS was bounded just to the application of

precast or prefabricated concrete structures. Only a few interviewees discussed other

materials, such as steel and timber. Moreover, participants misunderstood the term

“building” in relation to IBS, and believed it was only applicable to the construction

of the building. Instead, it refers to the “act of construction”. Thus, they disregarded

the presence of IBS application in infrastructure projects in their responses.


Regarding the drivers and challenges of IBS application, most of the interview

findings mirrored the academic literature. The significant benefits of IBS application

are time-saving, better quality, and high productivity. Other impetuses, such as cost-

effectiveness, improving safety, and environmental performance and policy

requirements were also frequently emphasised in the interviews. Even though these

tangible and intangible benefits shift the conventional practice to IBS implementation,

there are also some limitations. The interviews revealed that there are some elements

in IBS application that increase the cost, such as upfront investment in manufacturing

facilities, small scale projects, and custom-design components. In addition, several

technical aspects involve planning, designing, and supply chain difficulties, as well as

insufficient competent stakeholders, leading to conventional construction methods

being the preferred practice.

4.3.2 Applicability of IBS Adoption in Infrastructure Projects

What do infrastructure projects refer to?

By obtaining participants’ general ideas about infrastructure projects, the

interviews equipped the researcher with an initial impression of the term

“infrastructure” as determined by the interviewees. Figure 4-3 presents the

interviewees’ thoughts in relation to providing examples of built structures that they

referred to as “infrastructure projects”.

Figure 4-3: Example of infrastructure project referred by the interviewees


Based on these examples, participant’s understanding of infrastructure was in

agreeance with the Oxford Dictionary (2015) definition of infrastructure as “basic

physical and organisational structures and facilities needed for the operation of a

society or enterprise”. These are comprised of the physical structures of public

facilities that serve the public for certain purposes. For example, airports, seaports,

viaducts, car parks, bridges, tunnels, bus stations, jetties, roads, and depots are

transportation infrastructures. Court houses, schools, mosques, hospitals and fire

stations could be referred to as building-type infrastructures. Civil engineering works

such as dams and drainages were also mentioned. Even though some people classify

them as a “buildings” rather than “infrastructure”, it is important to realise that these

buildings do not exist in isolation, they are the pre-requisite facilities for social

development.

State of IBS application in infrastructure projects

The selection of a construction method depends on project characteristics, site

conditions, market attributes, as well as local regulations (Y. Chen et al., 2010a). Even

though the use of IBS offers significant advantages, IBS application is not necessarily

appropriate for every infrastructure project. While some of the interviewees argued

that it was uncommon to associate the application of IBS with infrastructure projects,

P3 and P19 claimed that IBS had been utilised, but was better-known by a different

term. P3 explained that:

“IBS in infrastructure is nothing new, but it was called a prefabricated

system. That’s it.” (P3)

The suitability of IBS adoption depends on which system has been chosen for a

certain application (P17). P10 pointed out that:

“You cannot have one system that can solve all [of] the problems. Every

system caters [for] certain needs of a project. In terms of looking to the

product perspective, it actually depends on the application of the

product that suits that particular project.” (P10)

IBS has been referred to as several types of systems, such as pre-cast concrete

systems, steel formwork systems, steel framing systems, prefabricated timber framing

systems, and block work systems (CIDB, 2003). Some interviewees (P1, P7, P12, P13,

P14, P15, P17, P19) mentioned some of products and components that demonstrate


IBS application in infrastructure projects. Basic structural components, such as

columns, beams, floor, and roof trusses are some of the typical applications found in

building-type infrastructures, such as hospitals, schools, mosques, fire station, court

houses and transit stations. This may be associated with the precast panel system,

concrete blocks, interlocking blocks, and load bearing structures. Some interviewees

(P2, P3, P6, P7, P11, P13, P19) also mentioned that structures such as piers, viaducts,

tunnels, and rail tracks had adopted IBS, as they use prefabricated components in

transport infrastructure projects. Such applications involve prefabricated components

such as segmental box girders, concrete blocks, tunnel linings, road edges, and

concrete slippers. Drainage systems also commonly use pre-cast U-drains, block drains

and culverts as the main construction components (P1, P3, P12, P13, P15). It is also

important to note that IBS is also applied in architectural components, used for

cladding, façade mullions, and glazing (P4, P7, P11, P12, P17). Moreover,

interviewees (P4, P5, P12, P13, P14) also revealed that IBS applications are not limited

to prefabricated components, but are also considered for reusable formwork systems

and modularised building services systems.

Factors of applicability for IBS adoption in infrastructure projects

Two main concerns highlighted by the interviewees for IBS adoption related to

cost and design factors. Addressing building-type infrastructure, P16 indicated that

IBS applicability depends on the type of building to be constructed. In contrast, the

majority of the interviewees claimed that IBS applies to any kind of project.

Conditionally, P1 and P2 justified that this is possible as long as economics of scale

are received. While this certainly affects the costs, it is influenced by various design-

related factors (Figure 4-4). For example, design standardisation and repetitive

component employment would provide higher volume for identical products (P3 and

P11). On the other hand, an aesthetic architectural design may require custom

formwork for their fancy-unique shapes (P13, P14, P15). For this reason, IBS is a

better choice to ensure the quality of components in terms of accuracy and precision.

This is also the case with structural designs with special requirements. An interviewee

stated that:

“Prefabrication is also used in cases when a unique design becomes so

complex that only by means of computerised methods of calculation and


fabrication is [it] possible to resolve intricate constructions being each

part different than the others.” (P7)

Figure 4-4: Factors contributes to IBS application in infrastructure project

However, P3 and P18 pointed out that sub-structure elements that impose

unpredictable soil condition risks were not appropriate for IBS, as this would not allow

for prompt design changes. Moreover, some interviewees also referred to the project

site condition to imply IBS applicability. For example, it was recommended that IBS

application be considered for hectic areas and high-density populations (P16). It is also

important to note that:

“The main factor that determines the applicability of prefabrication is

the availability of resources, and that includes the capacity of the design

of the team in charge of the development, [and that] the technology and

supply chain [are] available at the right cost for the capacity of the

investment.” (P7)

While IBS application is desirable for infrastructure projects, respective to the

above-mentioned conditions, the method of implementation is unique between

projects. The complexity of design requirements (P2, P6, P7, and P18) differs between

one project and another. This causes variation in the type of components or systems to

be used, the scale of repetitive elements, and the method of installation. For example:


“Due to the distance between the beams is (sic) very close to each other,

we use a system such [as the] half slab system. But if we compare to the

bigger building, such [as an] IKEA warehouse, which surely uses

precast, you can see the span is wider, especially at the parking lot area,

as they need to provide the clearance for the car park. So, they used [a]

hollow core, which the span can reach up to 16-18 meters. So, it should

look into the application of the building, also the appropriate type of

IBS that would be used”. (P14)

“They use different machinery. For example,[if] you want to install [a]

long span bridge; they use [a] gantry crane. They use different types of

cranes. For tall buildings, they use [a] tower crane.” (P13)

It was also noted that projects such as transport infrastructure development are

also usually located in a congested or urban area. P7 commented that:

“…due to the complexity of the infrastructure that requires the

construction of kilometres of tunnels and viaducts, as well as stations

that can be built either as part of the underground system or erected in

the viaduct, the construction method is mostly different than in ordinary

buildings.” (P7)

P19 also pointed out that infrastructure projects might have differences in term

of project monitoring, project planning, and project management based on which

procurement system is employed.

4.3.3 Strategies for IBS Implementation in Infrastructure Project Delivery

This interviews also provided information in relation to construction strategies

that could enhance the effectiveness, efficiency, and sustainability of IBS application.

The extracted remarks of the interviewees regarding the delivery strategies are

presented in Table 4-5.


Table 4-5: A summary of IBS delivery strategies mentioned by the interviewees

Construction Phase

Activities Delivery strategies mentioned by interviewees

Pre-Construction

Planning Establish an appropriate procurement method to be delivered, consider the role of [the] component supplier or fabricator as a part of the main stakeholders (P15)

Incorporate IBS consideration at the beginning of project planning (P6)

Client establish the design requirements to include IBS application (P2)

Plan for possible future changes or modifications (P14, P15)

IBS requires careful planning along the project execution (P12)

Design Accommodate component standardisation to increase [the] volume of identical components (P1, P2, P8, P10, P11, P13, P14, P15, P19)

Involves the component supplier/fabricator in the design process (P2)

Design for easy handling and transport (P2)

Client administers the design processes, which includes IBS application (P2)

Design for flexibility (future changes plan) (P14, P17)

Integrate BIM and facilities management consideration (P20)

Recognise the most appropriate system of IBS (e.g., frame system/block system/steel structure/modular etc.) to be used (P11, P17)

Incorporate lean design (P19)

Construction Phase

Component production

Emphasise the sustainability concept during component production (P7)

Engage with consistent supplier of raw material (P14)

Use adjustable steel formwork/mould (P16, P17)

Use rubber for flexible mould (P17)

Selection of material

Choose high-quality material for long-term performance (P2)

Consider steel structure as they got (sic) high recyclability (P11)

Consider light weight material (P12, P19)


Construction Phase

Activities Delivery strategies mentioned by interviewees

Selection of manufacturer

Choose manufacturer by considering their capacity of production – quality and quantity (P14, P17)

Choose the manufacturer that [is] located nearby to the project site (P11, P18, P19)

Material transportation and handling

Appoint on-site project coordinator to ensure product delivery scheduling in proper procedures (P12, P15, P18)

Conduct QA and QC during receiving the component/products (P17)

Schedule massive structure delivery during night time to avoid traffic disruption (P18)

Construction and Installation

Use self-launching erection method for such transport infrastructure projects that [are] located in congested area (P7)

Post-construction

Operation and Maintenance

Maintain and ensure the replacement parts are available in the market (P7, P15, P18)

Provide ‘Do’s & Don’t’ guideline for the owner for modification or renovation reference (P14)

Disassembly and Demolition

Disassemble prefabricated parts instead of demolishing to make recycling possible (P7)

The interviewees shared appropriate strategies that were not limited to the

perspectives of the stakeholders that they represented. It appears that their thoughts

were not biased solely to one-party interests. Most derived the recommendations based

on the obstacles and flaws of IBS implementation they had experienced.

As every stakeholder has claims, rights, and expectations, this can create

conflict. Some of the interviewees remarked that effective communication,

coordination, and cooperation between stakeholders were the key concerns to be

worked on in realising IBS application:

“Architects should tolerate towards (sic) [the] engineering aspect, work

together.” (P1)

“Coordination is very important.” (P2)

“IBS is a team effort. That means you [have] got to do the planning, the

design; you [have] got to incorporate the technology. You have to


incorporate the construction techniques during the planning and design

stage, only after then you could (sic) construct.” (P3)

“Tolerance between architect and engineers, structural and finishes.”

(P5)

In addition, Khamaksorn (2016) revealed that adequate knowledge about

scheduling and planning management, and essential skills in delegation, leadership,

decision making, and problem-solving are important for a successful project in the

construction industry. The interviewees consistently remarked that the success of IBS

implementation requires skills and experience that is not prescribed only to

construction workers, but also includes project management and the supplier:

“It is important to have a team that has the experience; they know how

integrating (sic) of project management of a planning of bridge or rail

construction and [it is] also inclusive of the building.” (P19)

“…the workers that are needed are skilled workers.” (P4)

“If they choose for (sic) IBS application from the beginning, [are] clear

on IBS, they can choose the team that is really experienced in IBS.”

(P15)

Therefore, the construction industry should equip construction workers with

relevant skills corresponding to emerging construction innovation and technology. At

the same time, they must provide and nurture the new generation of construction

students with applicable knowledge and skills, while building-up mutual collaboration

with the construction-related company to match industry needs.

“Engage with the supplier to provide regular training.” (P4)

“Our students could become the installer. We can call them as an

installers, not a labour (sic) anymore. Component installer. So, we can

sustain our own country.” (P11)

It is apparent that skills and experiences are remarkably essential to achieving

successful IBS implementation. The deficiency of holistic IBS-practice knowledge

may de-optimise the potential of IBS. An interviewee said:

“The level of knowledge must be very high, because the moment you do

wrong (sic) in your design or your planning, even when you produce


your product and the products are all faulty, then you may lose a lot of

money.” (P3)

From the responses of the interviewees, it is clear that incorporation of IBS in

construction projects requires additional concerns during the whole project life cycle.

4.3.4 Sustainability Potential of IBS in Infrastructure Projects

Sustainability has become a benchmark in the performance measurement of the

construction project, moving beyond cost, time, and quality satisfaction. Recent

project development has aimed to embrace the responsibility to the environment,

social, and entire economic aspects. For this reason, IBS adoption can be seen as an

alternative to achieve these objectives. It has competitive advantages in promoting

green construction, thus contributing to various aspects of sustainability (Hamid &

Kamar, 2012). As can be seen from these interviews, the researcher found several

aspects of IBS application that contribute to project sustainability, which included cost

efficiency, better quality, greater productivity, waste minimisation, health and safety

promotion, as well as adaptability.

Cost efficiency

As discussed in the previous section, IBS application accommodates cost

savings in some aspects. According to Bari, Yusuff, et al., (2012), factors that are

related to the project and IBS characteristics have the most influence on IBS project

costs. Even though cost savings are not necessarily achieved, there are some elements

that could enhance the project’s cost efficiency. Interviewees said that IBS could

reduce costs by eliminating unnecessary costs, such as utilisation of scaffolding and

dumping costs due to the presence of on-site leftover materials. P8 stated:

“Reduce the indirect cost that you do not need to (sic). If you use the

precast, of course, you do not need the scaffolding to be installed at the

site.” (P8)

The majority of participants agreed that one of the most significant contributions

of IBS is waste minimisation. Using conventional practice, the amount of raw material

on the construction site is not in the exact amount needed to be used. The leftover raw

material is abandoned on the project site.


“When you construct in a conventional way, they spend a lot of money

for disposal of such timber formwork, leftover concrete, and such

things.”(P2)

In some situations, such as improper storage arrangements and uncertain

weather conditions, raw materials may be exposed to damaging risks. One of the

interviewees complained:

“If you are ever working at the conventional project site, you will see

the timber are (sic) scattered all over the area. End of days, they are

exposed to the sun, damaged, and finally disposed of. Cannot be reused,

because they are already broken. If they ordered 100 tonnes of timber

for formwork, they actually, at last, will dispose [of] all of them.” (P1)

This scenario indirectly impacts on project costs. It seems that IBS is a better

option to manage such problems by optimising the raw material, which could therefore

reduce the amount needed. The interviewees stated:

“By using prefabricated components, we could reduce the usage of sand

and cement. IBS requires minimal raw materials than in-situ

techniques.” (P11)

“With proper planning, when you use precast, you can reduce the cost

in terms of materials used.” (P8)

In addition, the application of IBS through steel formwork systems encourages

re-use instead of the limited use of timber formwork. Moreover, at the end of their use,

steel formworks have a resale value for recycling utilisation. Some interviewees

remarked:

“For conventional, you will use plywood as the formwork and how many

times you could (sic) re-use them? After limited use, you have to throw

it away.” (P2)

“For the application of steel mould, it can be reused many times, it can

be recycled and even we (sic) can sell the mould if we do not want to use

it anymore.” (P15)

Another factor that contributes to cost efficiency is manufacturing the

prefabricated IBS component in mass production. Efficient production is achieved


when a product is created at the lowest average of the total cost. The quantity produced

and standardisation strongly influences the costs in addition to the production and

assembly technology used (Ehrlenspiel, Kiewert, & Lindemann, 2007). Thus, the more

similar components that are produced, the more cost savings can be achieved. Some

of the participants highlighted the impact of economy of scale to the project costs:

“If the economic scale [is] still not there, so that has not yet to (sic)

lower the price.” (P11)

“IBS can reduce project costs, depending on these two factors. First, the

scale of the project and by having the economical design.” (P16)

Regardless of the above factor, the benefit of IBS in delivering the project in a

shorter time frame is paid off the longer time consumed for the project planning at the

beginning of the project phase. Some of the participants remarked in their responses

that:

“[The] IBS project completion period could be shortened due to the

characteristics of IBS itself. So, when the time is shorter, labour wages

can be reduced, and this contributes to cost savings.” (P12)

“With IBS, you can shorten the period of the construction, which when

you can short (sic) it, it completes faster. Therefore, it is more

profitable.” (P16)

It is also important to realise that project delays will bring about significant cost

overrun (Abdul Rahman, Memon, & Abd Karim, 2013). While this absolutely impacts

project expenses, the return of investment would also be delayed. One interviewee

noted that:

“Fast construction resulting (sic) in rapid development. Thus, faster

financial return from development can be acquired.” (P16)

Quality

One of the methods to achieve construction objectives is through quality

performance. Quality in construction is influenced by the experience level of the

project consultant, the performance of the project costs and time, the effectiveness of

project planning and documentation, as well as the occurrence of errors or omissions

in the construction and project documents (Larsen, Shen, Lindhard, & Brunoe, 2016).


Errors during construction might occur due to various factors, such as design errors

and human errors. Human errors include insufficient knowledge, ignorance,

carelessness, negligence, forgetfulness, unclear responsibilities, relying on others, and

communication errors (Ortega & Bisgaard, 2000). In this regard, IBS offers an

appropriate solution to manage this possibility by replacing a labour-intensive process

with an industrialisation process. Factory production offers a better working

environment with better quality control and quality assurance. Interviewees mentioned

that:

“IBS controlling (sic) accidental construction and also falsework

during the construction phase.”(P5)

“Production of [the] components happens in the controlled yard with

high-quality assurance and quality control.” (P9)

In addition, with the availability of mechanised production tools, IBS delivers

high precision of measurement during the production process. This also provides the

ability to reach difficult areas, which are often unreachable in conventional

construction (Hamid & Kamar, 2012). This is also true in relation to the substitution

of conventional plywood formwork with the steel fabrication moulds, where the

quality of the finished product is more consistent. The interviewees also believed that

the workmanship of construction is easier to control. The interviewees remarked:

“Components can be produced with minimal tolerance, therefore less

touch up work is required.” (P16)

“But with IBS, we use [a] steel mould. It is more environmentally and

delivers better quality as well.” (P2)

Productivity

The high productivity of each of the construction activities generates efficient

performance of the construction process. Productivity in construction corresponds to

the ability to convert resources into a physical construct through utilisation of various

technologies and types of implementation (Durdyev & Ismail, 2016). The optimisation

of productivity requires that all aspects of the production process are scrutinised to

reduce unnecessary time and effort. This begins with proper planning for project

execution, which can occur during the design phase.


By implementing IBS, on-site construction activities are minimised and

simplified. Through substitution of labour-intensive processes to industrialisation

processes, IBS transfers the burden of construction process to the equipment and

machinery (P10). Managing messy concreting activities can then be shifted to the more

systematic-efficient production processes. This allows parallel progress of component

production with other on-site civil engineering work, which speeds up project

completion and prevents time loss due to weather delays.

In addition to the ability to produce large quantities of prefabricated components,

IBS is certainly more consistent in terms of product quality compared to on-site

fabrication. It is important to realise that manufacturing processes involve an

automation system that has minimal resource-constrained relationships between

activities and is less susceptible to human error (Lu & Wong, 2007), which

subsequently prevents double handling work and rework, as claimed by one

participant:

“When you have falsework or unintentionally [make a] mistake during

construction, [it] means you have to repeat the work or demolish the

work, which is more damaging.”(P5)

Therefore, the productivity of IBS predominantly depends on machinery as the

production resource. One of the interviewees was concerned that it was possible that

the construction industry would employ manufacturing-oriented working systems to

accelerate construction operations:

“Industrialisation allows the construction industry to have shift working

system.” (P16)

As some on-site construction activities have been replaced by factory

production, minimal labour is then required on the construction site (P12, P13, P15

and P20)

“IBS reduces the number of workers. So, that will lead to reducing the

usage of the resources.” (P13)

“We opt for semi-skilled with less number of (sic) people…” (P15)

On the other hand, the skill and experience level of the workforce has been the

most influential factor on on-site construction productivity (Durdyev & Ismail, 2016).


Differing from conventional construction, IBS requires at least semi-skilled workers

for its implementation (P15). This indirectly reduces the dependency on under-skilled

foreign labour, which has been a national debate for years. To achieve better

construction productivity would require the construction practitioner to ensure that

workers have the relevant capabilities (P15, P16). This would then also possibly lead

the local construction industry to gain a better reputation. Interviewees made the

following remarks regarding this:

“…we increase the expert or half experts.” (P15)

“Anyhow, this will result in advancement in job skills, which [will]

require us to learn more and improve ourselves due to shortage

demand”. (P16)

Waste minimisation

Development of infrastructure projects cause enormous deterioration to the

ecological environment through generation of construction waste. This may lead to

pollution at the construction site (P12). Substantial resolution to combat this issue will

move towards sustainable construction (Jamilus, Ismail, & Aftab, 2013). P2 and P9

were aware that IBS application is a remarkable potential solution of waste

minimisation. The interviewees stated that:

“Using IBS, the wastages are reduced, so that helps in terms of

environment.” (P2)

“IBS [is] recognised as green technology. It reduces debris and wastage

at [the] site, [and] reduces using scaffolding/propping and timber.”

(P9)

Although only two participants were concerned about the waste reduction

contribution in relation to sustainability, the majority of the interviewees also

acknowledged IBS's ability to reduce construction waste. Some claimed that IBS

application could reduce the consumption of certain materials.

“The use of IBS applications could minimise the usage of raw materials

such as timber, steel, cement, bricks, and others.” (P12)

Others also acknowledged that some construction accessories, such as

scaffolding, timber formwork, and temporary structures are no longer required on-site


because the prefabricated component is produced at the factory. Some interviewees

remarked that:

“IBS seems [to cause] less waste and [is] tidier compared to

conventional [methods] because you rarely see scaffolding and

proppings… If you go [to] the site which [has] been using precast, you

won’t see such leftovers. You won’t see the timbers and all, because we

precast it in the factory and then we just transport it to the site and then

we install it.” (P8)

“It can reduce the wastage on site. It can reduce the resources used to

construct or to install a structure.” (P13)

“If we implement IBS, let say precast concrete or modular construction.

They are produced at the factory, we would not have any leftover on

[the] construction site. So, it will minimise the wastages.” (P1)

“…material wastages reduction. Less formworks (timber) used on site

resulting [in] less disposal.” (P6)

Reduction of waste indirectly leads to avoidance of unnecessarily incurring costs

for disposal, such as waste transportation costs and dumping costs. This consequently

contributes to economic attributes in sustainability pillars.

“We do not have a lot of debris. No debris can be found on-site, so there

are also no transports required for dumping purposes” (P17)

It is important to note that waste in construction does not only focus on the

quantity of materials. Construction waste is also caused by improper design,

procurement processes, material handling, and during construction activities (Ikau,

Joseph, & Tawie, 2016). P20 believed that a manufacturing system with a proper

assembly line for IBS component production would minimises the wastage of

manpower resources.

Health and safety

The performance of health and safety is a significant benchmark for a successful

sustainable project. The adoption of IBS provides the Malaysian construction industry

with more efficient, cleaner, safer, and innovative working environments (Abas,

2015).


The most significant response by the majority of interviewees was that IBS

provides a cleaner construction site. As IBS uses the least raw materials and does not

require unrelated construction appliances to be on-site, very minimal housekeeping

activities are required while offering a safer working environment. Several

interviewees mentioned this in their responses:

“When you have less messy jobs, such as formworks, your site will

become cleaner. It will become cleaner and easy to arrange. Before this,

one of [the] general labour task is to clean up the site… Housekeeping

tasks will become less hassle… [A] cleaner site provides better safety

performance.” (P15)

“…less wastage of material lying around the construction site.” (P4)

“Our site is cleaner.”(P1 and P19)

“…reduce debris and wastage at the site.” (P9)

“We do not have a lot of debris. Or maybe [we] could consider that

there is no debris. No debris can be found on-site. So, there is also no

transportation required to dump away all the debris. The site will be

very clean, very tidy and very safe… Besides that, dirty constructions

will be removed. That [is] actually involved [in] the cost, where it can

save a lot from the unnecessary expenses.” (P17)

Most of the interviewees also commented on the advantages of what the

controlled environment of component production contributes to the environmental and

social sustainability. From a social perspective, the direct implication to public comfort

and safety becomes a critical point. P18 believed that factories have better-controlled

safety regulations than a construction site. In this regard, manufacturing facilities are

usually placed quite a distance from residential areas and are built in closed-restricted

settings. Some interviewees noted that:

“…when we talk about manufacturing in a factory, it is well gated, in

an industrial area, no residential [areas] nearby.”(P1)

“Components [are] produced at [the] casting yard. The raw materials

are brought onto, handled, and stored at the same location. So, that area

is restricted from the public.” (P18)


While this minimises on-site accidental risks to construction workers, it also

reduces potential nuisance to the surrounding neighbourhood, especially exposure to

noise and air pollution and heavy traffic conditions.

“If you use concrete, you cannot control the dust that comes from the

activities. This contributes to construction pollution. The implication to

the environment, it does not just relate to dust and debris, but another

concern is noise pollution.” (P11)

“… minimised disruption to the site neighbourhood areas, [which]

includes heavy traffic [caused] by the frequent delivery of raw

materials”. (P7)

Factory-control and industrialisation were also perceived to improve the

environmental performance of a project (Steinhardt & Manley, 2016). Consequently,

P19 noted that providing a better construction environment through IBS

implementation could reduce the perception of society in regards to the construction

profession being dirty, difficult, and dangerous.

Adaptability

Some interviewees were aware of and recognised the potential of IBS towards

adaptability for future changes. In relation to long-term projection, most of the

interviewees highlighted that the maintenance of built facilities, either buildings or

infrastructures in general, is essential good planning. This should take place in the

operational phase, and several terms were pointed out by the interviewees regarding

maintenance activities, such as extension, renovation, and modification.

The selection of the appropriate IBS system to be adopted for a certain project

depends on the function and prospect of the building or infrastructure to be built. As

noted by the interviewees (P2, P14, and P17), initial intention and good planning for

future potential changes is important to ensure the capability of IBS can be optimised

from the early design phase. For example, buildings that use steel structures are more

flexible for modification than a pre-cast concrete system. The simplicity of connection

between steel structures, usually dry-connections, allows for easier dismantling of the

components in contrast to a pre-cast concrete structure that involves grouting for the

connections. One interviewee noted:


“If you have the intention to build it as a temporary structure, then it is

better [that] you select the steel IBS, and it is also better than you select

a concrete design system.” (P2)

Consequently, P10 and P11 discussed the contribution of the ease of dismantling

as a practice towards sustainability through the recyclability of the components. The

advantage of dismantling also makes it possible to relocate a building that is fully built

using IBS (P10). This situation may occur rarely in Malaysia, because most buildings

are built to be permanent. However, this concept could be applied to a temporary

structure, and at the end of use, the components could potentially be reused or recycled,

which would avoid the generation of waste through demolition activities.

On the other hand, interviewees P11, P17, and P18 provided examples related to

how the IBS application has made the modification process easier. P17 and P18

acknowledged the capability of IBS-built structures to accommodate new additional

structures for expansion and extension purposes, either horizontally (e.g., extension of

rail tracks) or vertically (e.g., creating additional car park spaces by increasing the

floor level of the multi-storey car park). Meanwhile, P11 explained the relevance of

proper component demounting in demolition:

“…For example, [if] we build a train station with parking area.

Actually, the station and the parking space are combined structurally.

Based on the project requirement, [the] lifespan requirement for [a]

station [is] up to 120 years, while for parking [it is] only 50 years. So,

we have to allow [for] safe demolition for parking without affecting

[the] station. So, how we can (sic) do that? By IBS... that is why we use

[the] IBS system, so that we can dismantle later on, easier.” (P11)

However, in contrast, P19 argued whether this was practical for all project types

and sizes. As the study and application of IBS is still emerging, the performance of

used components for reuse or recycling requires further examination.

4.4 SUMMARY

This chapter presented the processes used for and the results from the semi-

structured interviews. Twenty targeted construction practitioners with IBS experience

were interviewed. They represented various stakeholders in the Malaysian


construction industry and provided a holistic view of the local industry’s perception.

The semi-structured interviews validated the preliminary conceptual research

framework that was developed based on literature studies (see Figure 2-12).

This chapter provides a holistic view on local industry’s perceptions and

understanding about IBS application and infrastructure projects. Majority of the

interviewees associated IBS with the process of industrialising the construction

components under a controlled environment, with transportation of the products then

taking over before installation takes place on the construction site. They believed that

time efficiency, quality, productivity, safety, environmental performance, technical

and regulation requirement are the drivers of implementation of IBS. However, they

also recognised some challenges in its implementation in term of cost, technical issues

as well as lack of competencies and awareness among construction practitioners.

The interviewees believed that IBS application in infrastructure projects are

relevant by highlighting its application in various construction projects such as

airports, tunnels, bridges, rail tracks and others which considered as built

infrastructures. They revealed that the applicability of IBS in infrastructure projects

depends on the types of IBS, the type of components used and how the system suits to

a particular type of project. Besides, there are other criteria that need to be attended to

which comes from design requirement and site condition. The interviewees also shared

the appropriate strategies that could enhance the effectiveness, efficiency and

sustainability of IBS application from planning and design stage, component

production, material transportation and handling, construction and installation until

post-operation phase. Accordingly, the interviews discovered that IBS application

could contribute to the project sustainability in term of cost, quality, productivity,

waste minimisation, health and safety as well as adaptability capacity.

Overall, the interviews give a satisfactory overview about the understanding and

perception of IBS application in infrastructure projects and its contribution to the

project developments. Correspondingly, the findings from the interviews helped

identify the appropriate items for the development of a questionnaire survey for the

Delphi study in the next chapter.

Chapter 5: Results of the Delphi Study 157

Chapter 5: Results of the Delphi Study

5.1 INTRODUCTION

This chapter reports the results of the two-round Delphi survey. The Delphi

survey was conducted with the objective to: (1) examine the level of agreement

amongst the panellist to determine the relevant and critical items, and (2) associate the

judgements from different perspectives of panellist subgroups. The Delphi results then

led to the formation of a comprehensive framework integrating the redevelopment

potential into the sustainable delivery strategies of IBS implementation, as illustrated

in Figure 5-1. This chapter begins by presenting the panellists’ profiles, followed by

the results and findings for each round of the Delphi survey, and the reliability

examination. Finally, the findings of the Delphi surveys are summarised.

Figure 5-1: The role of Delphi study in framework development process

158 Chapter 5: Results of the Delphi Study

5.2 PROFILE OF DELPHI PANELLISTS

A total of 25 potential panellists, including construction project owners,

consultants, contractors, suppliers, and academics or working at research bodies was

targeted. Five potential participants from each group were approached. Fifteen of the

potential panellists expressed their interest and agreed to participate – a 68%

participation rate. However, two of the 15 panellists ceased their participation after the

first round of the Delphi survey, leaving only 13 panellists at the completion of the

Delphi study. The participants represented a wide spectrum of the construction

industry. The panellists comprised three representatives who were project clients or

developers, four consultants or designers, four contractors, two suppliers or

manufacturers, and two IBS researchers from an academic institution, as shown in

Figure 5-2. The composition of the panellist profiles, with diverse backgrounds,

experience, and involvement infers substantial holistic and balanced perspectives.

Figure 5-2: Composition of Delphi panellists by category

Table 5-1 presents a summary of the Delphi panellists’ profiles. The panellists

had at least five years and up to 35 years’ experience in construction industry. Nine of

the panellist had at least 10 years’ experience in infrastructure projects. Even though

D5 had very minimal experience in project implementation, this panellist had a strong

research background and expertise in IBS-related studies.

Client/Developer, 20%

Contractor, 27% Consultant/Designer, 27%

Manufacturer/Supplier, 13%Research/Academic

Institution, 13%


Tab

le 5

-1: P

rofi

les

of th

e D

elph

i pan

elli

sts

Pan

el

ID

Pos

itio

n

Org

anis

atio

n

Exp

erie

nce

in

con

stru

ctio

n

ind

ust

ry (

year

s)

Exp

erie

nce

in

Infr

astr

uct

ure

p

roje

ct (

year

s)

Pro

fess

ion

al

Bod

y M

emb

ersh

ip

Com

mit

tee

mem

ber

ship

C

onfe

ren

ce

pre

sen

tati

on

Pee

r re

view

jo

urn

al

arti

cle

Boo

k/b

ook

chap

ter

auth

orsh

ip

Ad

van

ced

d

egre

e

D1

Fac

ilit

y m

anag

er

Cli

ent/

deve

lope

r 10

10

✓

✓

B

D2

Qua

ntit

y S

urve

yor

Con

trac

tor

14

14

✓

M

D3

Sen

ior

Eng

inee

r C

onsu

ltan

t/de

sign

er

18

18

✓

✓

B

D4

Dir

ecto

r C

onsu

ltan

t/de

sign

er

35

35

✓

✓

✓

✓

M

D5

Res

earc

her

Res

earc

h/ac

adem

ic

inst

itut

ion

5 1

✓

✓

✓

✓

✓

P

D6

Pro

ject

man

ager

C

lien

t/de

velo

per

17

14

✓

B

D7

Sen

ior

Eng

inee

r C

onsu

ltan

t/de

sign

er

9 7

✓

B

D8

Pro

ject

man

ager

C

ontr

acto

r 11

8

✓

B

D9

Eng

inee

r C

onsu

ltan

t/de

sign

er

5 5

✓

M

D10

P

roje

ct m

anag

er

Con

trac

tor

15

3 ✓

✓

B

D11

R

esea

rche

r R

esea

rch/

acad

emic

in

stit

utio

n 30

10

✓

✓

✓

✓

✓

P

D12

C

onst

ruct

ion

Man

a ger

Con

trac

tor

15

15

✓

M

D13

G

ener

al m

anag

er

Man

ufac

ture

r/

supp

lier

35

20

✓

✓

M

D14

D

esig

n m

anag

er

Cli

ent/

deve

lope

r 7

5 ✓

B

D15

D

irec

tor

Man

ufac

ture

r/

supp

lier

35

35

✓

✓

✓

B

*B –

Bac

hel

or

M –

Mas

ters

Deg

ree

P –

Ph

D


5.3 RESULTS AND FINDINGS OF DELPHI STUDY

In Round 1 of the Delphi survey, 78 items from seven questions were classified

under category 1 (see Table 3-10). The items under this category were considered very

relevant to their respective questions, with agreement from a majority of the panellists.

None of the items were considered irrelevant (under criteria 2), while 49 items (under

category 3) were considered for re-rating in the subsequent round.

Consensus was reached for 29 out of 49 items and these were agreed as being

relevant after re-assessment in Round 2. This was taken as an indication of agreement

between the panellists, as there was a significant improvement in the number of items

that reached consensus.

The results of the Delphi study are presented separately for each of the seven

questions. Two types of corresponding tables summarise the results for each question:

(1) rating the results with the value of interquartile range and level of agreement for

each item in both Round 1 and Round 2, and (2) the mean rating results by subgroup.

The results obtained after two rounds of the Delphi survey are outlined with further

explanations whenever possible. The respective items for each question (whichever

appropriate) are then ranked in order of relevance according to their mean ratings and

presented in respective bar charts.

5.3.1 Exploration of IBS Application in Infrastructure Development

Despite being a promising method of construction that contributes to sustainable

development, scant literature regarding IBS in infrastructure projects was found. Thus,

to explore more detailed information, some issues were further examined. This

subsection discusses the first three questions, identifying the consideration factors,

drivers, and challenges in relation to IBS application in infrastructure projects.

Consideration factors for IBS adoption in Infrastructure projects

Firstly, Table 5-2 shows the results of the panellists’ ratings for the factors that

need to be considered when adopting IBS in infrastructure projects for Round 1 and

Round 2 of the Delphi survey. In Round 1, all of the factors were considered important

by the panellist, with the level of agreement set as more than 60%. However, five of

the factors did not reach consensus in this round, as the IQR value was more than 1.0.

There were no additional factors suggested by the panellists.


The factors that did not reach consensus in Round 1: “cost of project”,

“requirement of project developer”, “availability of local material”, “type of

procurement system”, and “lifespan of project” were included in the Round 2 Delphi

questionnaire to be reassessed by the panellists, and achieved better agreement.

However, “lifespan of project” and “type of procurement system” still did not reach

consensus, as they did not comply with the cut-off value for the IQR and the percentage

of agreement, respectively. A total of 17 consideration factors were compiled and the

mean rating of each item was calculated.

Table 5-2: Rating results for the consideration factors for adopting IBS

Items IQR Level of agreement (%) Reached

Consensus? Not important Important

ROUND 1

1 Specification of designed components or panels (e.g., size, dimension)

1.0 0% 100% YES

2 Repetitiveness of structural component design 1.0 0% 100% YES

3 Repetitiveness of architectural component design and features

1.0 0% 100% YES

4 Application of standardised structural components or panels

1.0 0% 93% YES

5 Requirement of government policy 1.0 0% 87% YES

6 Selection of appropriate IBS system 1.0 0% 93% YES

7 Application of standardised architectural components or panels

1.0 0% 93% YES

8 Availability of competent manufacturer or supplier

1.0 0% 93% YES

9 Location of project site 1.0 7% 80% YES

10 Type of infrastructure projects 1.0 0% 87% YES

11 Availability of competent contractor 1.0 0% 87% YES

12 Project size 1.0 7% 87% YES

13 Availability of competent designer 1.0 7% 87% YES

14 Availability of appropriate technology 1.0 0% 80% YES

15 Cost (contract sum) of project 2.0 7% 73% NO

16 Requirement of project developer 2.0 0% 73% NO

17 Availability of local materials 2.0 0% 73% NO

18 Type of procurement system 2.0 7% 67% NO

19 Lifespan of project 2.0 7% 67% NO

ROUND 2

1 Cost (contract sum) of project 1.0 - 100% YES

2 Requirement of project developer 1.0 - 85% YES

3 Availability of local materials 1.0 - 92% YES

4 Type of procurement system 1.0 - 54% NO

5 Lifespan of project 1.0 - 77% NO


Table 5-3 presents the mean rating for each item according to the panellists’

categories. The necessity of the factors is ranked according to the value of their mean

ratings. As can be seen, all of the items were relatively important, with a mean rating

above 4.00. There were some remarkable ranking variations amongst the panellists’

subgroups. The contractor subgroup uniquely attributed the most important

consideration factor to be “type of infrastructure project”, while the consultant, client,

researcher, and manufacturer subgroups ranked this 7th, 8th, 12th, and 15th, respectively.

However, the contractor subgroup perceived “requirement of government policy” to

be the lowest attributable factor to be considered. This is not surprising, as the

government policy for IBS in Malaysia does not apply to anything other than building

construction projects, while this research pertained to infrastructure projects as a

whole. The contractor and manufacturer subgroups highly ranked “availability of

competent contractor” as the 3rd and 4th most important factors to be considered for

IBS application, while the other subgroups ranked this 8th, 12th, and 15th, respectively.

Most panellist subgroups believed that “cost of project” was an important factor before

deciding to adopt IBS. However, from the manufacturer’s perspective, project cost was

not really an issue. This seems reasonable, as manufacturers focus only on the

production phase and the remaining project phases do not significantly influence their

financial burden.


Table 5-3: Mean ratings for consideration factors by panellist subgroup

Item

All panellist

Clients Contractor Consultant Manufacturer Researcher

Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank

Specification (e.g., size, dimension) of designed components (or panels) 4.60 1 4.67 3 4.50 4 4.75 1 4.50 3 4.50 2

Repetitiveness of structural component design 4.60 1 4.67 3 4.50 4 4.50 3 4.50 3 5.00 1

Cost (contract sum) of project 4.54 3 5.00 1 4.67 2 4.50 3 4.00 10 4.50 2

Repetitiveness of architectural component design and features 4.53 4 4.33 8 4.50 4 4.75 1 4.50 3 4.50 2

Requirement of government policy 4.47 5 5.00 1 4.00 17 4.25 7 5.00 1 4.50 2

Application of standardised structural components (or panels) 4.47 5 4.67 3 4.50 4 4.50 3 4.00 10 4.50 2

Selection of appropriate IBS system 4.40 7 4.33 8 4.25 14 4.25 7 5.00 1 4.50 2

Location of project site 4.33 8 4.67 3 4.25 14 4.50 3 3.50 15 4.50 2

Application of standardised architectural components (or panels) 4.33 8 4.33 8 4.50 4 4.25 7 4.00 10 4.50 2

Availability of competent manufacturer or supplier 4.33 8 4.33 8 4.50 4 4.25 7 4.50 3 4.00 12

Type of infrastructure projects 4.27 11 4.33 8 4.75 1 4.25 7 3.50 15 4.00 12

Requirement of project developer 4.23 12 4.50 7 4.67 2 4.00 13 4.50 3 3.50 17

Availability of competent contractor 4.20 13 4.33 8 4.50 4 3.75 15 4.50 3 4.00 12

Availability of local materials 4.15 14 4.00 16 4.33 13 4.00 13 4.00 10 4.50 2

Project size 4.13 15 4.33 8 4.50 4 3.50 16 4.00 10 4.50 2

Availability of competent designer 4.13 15 4.33 8 4.50 4 3.50 16 4.50 3 4.00 12

Availability of appropriate technology 4.07 17 4.00 16 4.25 14 4.25 7 3.50 15 4.00 12

Overall, the top five most important factors to be considered for IBS adoption

were “specification of designed components or panel”, “repetitiveness of structural

component design”, “cost of project”, “repetitive of architectural component design

and features”, and “requirement of government policy”. Three of these were

categorised under design requirements (see Figure 3-16). The categorical chart in

Figure 5-3 also shows that design requirements was the most important consideration

factor when deciding about IBS application. Meanwhile, the five lowest ranked factors

were “availability of competent contractor”, “availability of local materials”, “project

site”; “availability of competent designer”, and “availability of appropriate

technology”. The majority of these items represent industry capacity.


Figure 5-3: Consideration factors of IBS for infrastructure projects by category.

Drivers of IBS application in infrastructure projects

The possible drivers and challenges of IBS application were summarised from the

literature and semi-structured interviews. They were then rated by the panellists and

the results are presented in Table 5-4 and Table 5-6. In Round 1, approximately 60%

of the driver items reached at least 60% agreement for being relevant as determined

by the panellists. However, five of these items had an IQR of more than 1.0, which

indicates the ratings scored by the panellists were highly varied. Therefore, only 13

out of 29 items were considered as having reached consensus in this round, leave 14

items for reassessment in Round 2.

The agreement between the panellists in Round 2 improved. The variation of the

rating score for each item was smaller, which was represented by a decrease in the IQR

value. “Produce better construction quality” achieved total agreement in this round.

Additionally, another nine items also reached consensus. Two items (“Offer

dismantling ability” and “Increase property value”) did not achieve at least 60%

agreement, while the remaining items had high variation in the scored ratings.

4.00 4.10 4.20 4.30 4.40 4.50

Design Requirement

Policy


Industry Capacity

Consideration factors by category


Table 5-4: Rating results for the drivers of IBS application in infrastructure projects

Items IQR

Level of agreement (%) Reached

Consensus? Not Agree Agree

ROUND 1

1 Speed-up on-site construction activities 1.0 0% 100% YES

2 Reduce dependency on manpower 1.0 0% 100% YES

3 Simplify construction activities 1.0 0% 100% YES

4 Reduce wastage 1.0 0% 100% YES

5 Allow simultaneous site preparation and construction works (components or panels production)

1.0 0% 100% YES

6 Optimise material consumption 1.0 0% 93% YES

7 Improve quality control system 1.0 0% 93% YES

8 Minimise weather-related delays 1.0 0% 80% YES

9 Reduce energy consumption 1.0 0% 80% YES

10 Reduce emission 1.0 0% 80% YES

11 Improve constructability 1.0 0% 80% YES

12 Produce better construction quality 2.0 7% 73% NO

13 Minimise nuisance (e.g., noise, dust, and traffic disturbance) to site neighbourhood

2.0 7% 73% NO

14 Improve recyclability of components (or panels) 2.0 13% 67% NO

15 Reduce life cycle cost 2.0 0% 60% NO

16 Qualify for financial incentives 1.0 7% 73% YES

17 Improve competitive capacity 1.0 0% 67% YES

18 Government policy 0.0 13% 80% YES

19 Reduce space required for material inventory 1.0 20% 67% YES

20 Client's requirement 1.0 7% 53% NO

21 Offer dismantle ability 2.0 7% 47% NO

22 Provide safer working environment 2.0 27% 67% NO

23 Increase speed of return of investment 1.0 20% 53% NO

24 Reduce trips of material transportation 1.0 20% 53% NO

25 Ensure project cost certainty 1.0 20% 53% NO

26 Increase customisation options for special and complex design requirements

1.0 20% 33% NO

27 Offer flexibility 3.0 40% 40% NO

28 Reduce construction cost 2.0 33% 40% NO

29 Increase property value 2.0 27% 27% NO

ROUND 2

1 Produce better construction quality 1.0 0% 100% YES

2 Minimise nuisance (e.g., noise, dust, and traffic disturbance) to site neighbourhood

0.5 0% 92% YES

3 Improve recyclability of components (or panels) 0.5 0% 77% YES

4 Reduce life cycle cost 0.0 0% 85% YES


Items IQR



5 Client's requirement 0.5 0% 77% YES

6 Offer dismantle ability 1.0 15% 54% NO

7 Provide safer working environment 1.0 8% 77% YES

8 Increase speed of return of investment 1.0 8% 92% YES

9 Reduce trips of material transportation 1.5 8% 62% NO

10 Ensure project cost certainty 1.0 8% 69% YES

11 Increase customisation options for special and complex design requirements

0.0 8% 85% YES

12 Offer flexibility 1.5 23% 62% NO

13 Reduce construction cost 1.0 16% 69% YES

14 Increase property value 1.0 8% 38% NO

All 25 driver items that reached consensus were collated, and the mean value for

each item was calculated. Table 5-5 presents the tabulation of the mean ratings of the

IBS drivers according to the panellists’ categories.

Although the overall ratings across the subgroups in different roles were

considered insignificant, there was still some variation within the rankings. The client

subgroup ranked both “reduce energy consumption” and “reduce emission” as the 3rd

most substantial drivers, whereas the other subgroups ranked them considerably lower.

It is noted that these items attribute to environmental factors. This is understandable

because commitment to environmental awareness has become an important

organisational asset to project developers to establish a higher standing in the industry.

The contractor subgroup ranked “reduce life cycle cost” as the 4th most

significant driver, whereas the other subgroups of clients, consultants, manufacturers

and researchers ranked this item as 13th, 18th, 15th, and 14th, respectively. “Reduce

construction cost” received the lowest ranking from the panellists. It can be assumed

that the majority of panellists were unsure about the extent and practicality of IBS in

minimising project expenses. However, the builder and contractor subgroups believed

that IBS has the ability to “increase speed of return of investment” to drive the

application of IBS in infrastructure projects.

The consultant subgroup ranked “optimise material consumption” as the main

driver of the IBS application in infrastructure projects, while the clients, contractors,

manufacturers, and researchers rated this 8th, 15th, 5th, and 14th, respectively. It is also


notable that the consultants rated “increase customisation options for special and

complex design requirements” higher than the other subgroups. Meanwhile, from the

manufacturers’ perspective, the item “simplify construction activities” was ranked

15th, which was in contrast to the other subgroups, who rated this item in the top three

ranks.

Table 5-5: Mean ratings for the drivers by panellist subgroup

Items

All panellist



Speed-up on-site construction activities 4.67 1 5.00 1 4.50 2 4.50 2 5.00 1 4.50 2

Reduce dependency on manpower 4.53 2 4.33 8 4.75 1 4.50 2 4.50 5 4.50 2

Simplify construction activities 4.47 3 4.67 3 4.50 2 4.50 2 4.00 15 4.50 2

Reduce wastage 4.47 3 5.00 1 4.00 9 4.50 2 4.50 5 4.50 2

Produce better construction quality 4.38 5 4.50 7 4.33 4 4.25 7 4.50 5 4.50 2

Allow simultaneous site preparation and construction works (components or panels production)

4.33 6 4.33 8 4.25 8 4.25 7 5.00 1 4.00 14

Optimise material consumption 4.27 7 4.33 8 3.75 15 4.75 1 4.50 5 4.00 14

Improve quality control system 4.27 7 4.00 13 4.00 9 4.50 2 4.50 5 4.50 2

Minimise weather-related delays 4.20 9 4.33 8 4.00 9 3.75 18 5.00 1 4.50 2

Minimise nuisance (e.g. noise, dust, and traffic disturbance) to site neighbourhood 4.15 10 4.00 13 4.33 4 3.75 18 4.50 5 4.50 2

Increase speed of return of investment 4.15 10 4.00 13 4.33 4 3.75 18 4.00 15 5.00 1

Reduce energy consumption 4.13 12 4.67 3 3.75 15 4.00 13 4.50 5 4.00 14

Reduce emission 4.13 12 4.67 3 4.00 9 4.00 13 4.50 5 3.50 19

Improve constructability 4.13 12 4.00 13 3.50 20 4.25 7 5.00 1 4.50 2

Reduce life cycle cost 4.00 15 4.00 13 4.33 4 3.75 18 4.00 15 4.00 14

Provide safer working environment 3.92 16 4.00 13 3.67 17 3.75 18 4.00 15 4.50 2

Qualify for financial incentives 3.87 17 4.33 8 3.50 20 4.25 7 4.00 15 3.00 24

Improve competitive capacity 3.87 17 4.00 13 3.25 22 4.00 13 4.00 15 4.50 2

Improve recyclability of components (or panels) 3.85 19 3.50 25 3.67 17 3.75 18 4.00 15 4.50 2

Client's requirement 3.85 19 4.00 13 3.67 17 4.25 7 3.50 23 3.50 19

Government policy 3.80 21 4.67 3 3.25 22 4.00 13 4.50 5 2.50 25

Ensure project cost certainty 3.77 22 4.00 13 4.00 9 3.75 18 3.50 23 3.50 19

Increase customisation options for special and complex design requirements 3.77 22 4.00 13 3.00 24 4.25 7 3.50 23 4.00 14

Reduce space required for material inventory 3.67 24 3.67 24 3.00 24 4.00 13 4.50 5 3.50 19

Reduce construction cost 3.62 25 4.00 13 4.00 9 3.00 25 4.00 15 3.50 19

Overall, it is apparent that the top five and bottom five IBS drivers were

consistently rated accordingly. Figure 5-4, demonstrates that the high rated drivers of


IBS application were related to construction productivity. On the other hand, the

factors “cost”, “policy”, and “others” ranked substantially lower.

Figure 5-4: Drivers of IBS for infrastructure project by category.

Challenges of IBS application in infrastructure projects

All items relating to challenges in IBS application in infrastructure projects were

rated, and the results are provided in Table 5-6. It can be seen that very few items

reached consensus in Round 1 of the Delphi survey, with only seven items reaching

consensus. Meanwhile, the remaining 11 challenges that achieved 60% of agreement

for being relevant had high variation in ratings in this round. Moreover, five items

were questionable in regards to whether the agreement was relevant or still unclear.

Therefore, a total of 16 items relating to challenges were included in the second round

of the survey.

In Round 2, the majority of the items achieved better agreement for being

relevant; however, only 11 items achieved at least 60% agreement. Based on the IQR

values, nine items were found to reach consensus at the end of Round 2, with a total

of 16 items recognised as the challenges of IBS applications in infrastructure projects.

3.30 3.50 3.70 3.90 4.10 4.30 4.50

Productivity

Quality

Environmental

Safety & health

Technical & design

Cost

Policy & requirement

Others

Categorical ranking for the driver of IBS application in infrastructure projects


Table 5-6: Rating results for the challenges of IBS application in infrastructure projects



ROUND 1

1 Uneconomic for small-scale project 1.0 13% 87% YES

2 Lack of experience 1.0 7% 80% YES

3 High capital investment 1.0 7% 80% YES

4 Highly restrictive construction tolerances 2.0 13% 73% NO

5 Lack of structural and architectural design integration

2.0 20% 73% NO

6 Negative perception and sceptism 2.0 7% 67% NO

7 Insufficient knowledge 2.0 20% 73% NO

8 Inflexible design changes 1.0 13% 67% YES

9 Lack of flexibility 2.0 13% 67% NO

10 Lack of codes and standard of application 1.0 20% 80% YES

11 Poor cooperation between stakeholders 2.0 20% 73% NO

12 Poor communication between stakeholders 2.0 20% 73% NO

13 Inappropriate procurement practices 3.0 27% 73% NO

14 Abundance of cheap labour 1.0 13% 60% YES

15 Limited variability of standard components (or panels)

2.0 20% 67% NO

16 Poor integration for the supply chain 1.0 13% 60% YES

17 Longer lead times for definite project planning and design phase

2.0 27% 53% NO

18 Restrictive for aesthetic and complex design 2.0 27% 60% NO

19 Insufficient on-site space for temporary component inventory

2.0 27% 53% NO

20 Lack of opportunities for standardisation and repetition in design

2.0 33% 60% NO

21 Remote project site 3.0 40% 47% NO

22 Lack of special equipment or technology 2.0 33% 27% NO

23 Poor quality products of components (or panels) 2.0 53% 20% NO

ROUND 2

1 Highly restrictive construction tolerances 0.5 - 85% YES

2 Lack of structural and architectural design integration

1.0 - 69% YES

3 Negative perception and scepticism 1.0 - 62% YES

4 Insufficient knowledge 2.0 - 69% NO

5 Lack of flexibility 2.0 - 54% NO

6 Poor cooperation between stakeholders 1.0 - 62% YES

7 Poor communication between stakeholders 1.0 - 54% NO

8 Inappropriate procurement practices 1.0 - 62% YES

9 Limited variability of standard components (or panels)

1.5 - 69% NO




10 Longer lead times for definite project planning and design phase

1.0 - 69% YES

11 Restrictive for aesthetic and complex design 1.0 - 62% YES

12 Insufficient on-site space for temporary component inventory

2.0 - 54% NO

13 Lack of opportunities for standardisation and repetition in design

2.0 - 54% NO

14 Remote project site 1.0 - 62% YES

15 Lack of special equipment or technology 1.0 - 62% YES

16 Poor quality products of components (or panels) 1.5 - 46% NO

Table 5-7 demonstrates the mean rating results and the ranking of the items

respectively. Based on overall ratings, only four challenges were highly rated (mean ≥

4.0): “uneconomic for small-scale project”, “lack of experience”, “high capital

investment”, and “highly restrictive construction tolerances”. It is noted that two of

these challenges related to cost consideration. This finding confirmed that the least

favourable driver factors of IBS implementation had become the strongest challenges

of implementing IBS in infrastructure projects.

Table 5-7: Mean ratings for the challenges by panellist subgroup

Items

All panellist



Uneconomic for small-scale project 4.27 1 4.33 3 4.75 1 3.25 15 4.50 1 5.00 1

Lack of experience 4.20 2 4.67 1 4.25 6 4.75 1 2.50 12 4.00 4

High capital investment 4.07 3 3.67 9 4.25 6 3.75 5 4.00 3 5.00 1

Highly restrictive construction tolerances 4.00 4 4.50 2 4.33 2 3.75 5 3.00 9 4.50 3

Inflexible design changes 3.73 5 3.67 9 4.00 8 4.25 2 2.50 12 3.50 5

Lack of codes and standard of application 3.73 5 4.33 3 3.50 15 4.25 2 2.50 12 3.50 5

Inappropriate procurement practices 3.69 7 3.50 11 4.00 8 3.75 5 4.00 3 3.00 12

Lack of structural and architectural design integration 3.69 7 4.00 5 4.00 8 3.75 5 3.00 9 3.50 5

Lack of special equipment or technology 3.69 7 3.50 11 4.33 2 3.75 5 3.00 9 3.50 5

Remote project site 3.69 7 4.00 5 4.33 2 3.25 15 3.50 6 3.50 5

Negative perception and scepticism 3.69 7 3.50 11 4.00 8 3.75 5 4.00 3 3.00 12

Poor cooperation between stakeholders 3.62 12 3.50 11 4.00 8 3.75 5 3.50 6 3.00 12

Abundance of cheap labour 3.60 13 4.00 5 3.00 16 4.00 4 3.50 6 3.50 5

Restrictive for aesthetic and complex design 3.54 14 4.00 5 4.33 2 3.50 14 2.00 16 3.50 5

Poor integration for the supply chain 3.53 15 2.67 16 3.75 14 3.75 5 4.50 1 3.00 12

Longer lead times for definite project planning and design phase 3.46 16 3.50 11 4.00 8 3.75 5 2.50 12 3.00 12


The consultant subgroup ranked “uneconomic for small-scale project” as the 2nd

lowest factor, while the client, contractor, manufacturer, and researcher subgroups

ranked this item in the top three. This may reflect that consultants could make any

design possible, regardless of the size of the project. While the supplier and contractor

deal with the volume of resources, the client, being the investor, may find that IBS

application costs more, especially for custom design. Another notable point is that the

manufacture subgroup rated “lack of experience” very low compared to the other

subgroups. Meanwhile, they ranked “poor integration for the supply chain” as the top

rank compared to the other subgroups. This could be explained because manufacturers

have long been established, while on the other hand, as a supplier they deal with the

delivery, transportation, and inventory of the construction components or products.

It can also be observed that the manufacturer representatives rated four items

below 3.0, which indicates that they disagreed that “lack of experience”, “inflexible

design changes”, “lack of codes and standard of application”, and “restrictive for

aesthetic and complex design” were challenges for IBS application in infrastructure

projects. This is understandable because manufacturers are producers of the IBS

products and responsible for ensuring the requests of their client are possible.

Most of the challenges were rated between 3.0 to 4.0. This suggests that many

of the challenges made it difficult for the panellists to decide whether they were

relevant or not. According to Figure 5-5, “cost” was the most critical challenge for IBS

application, followed by “knowledge and experience” and “design factors”. By

comparing the rating for the drivers and challenges, the researcher determined that the

drivers were considerably more prominent than the challenges in this study.

Figure 5-5: Challenges of IBS for infrastructure project by category.

3.40 3.50 3.60 3.70 3.80 3.90 4.00

Cost

Knowlegde & experience

Design

Resources

Site constraint

Project delivery

Coordination & communication

IBS challenges by category


5.3.2 Identification of IBS Contribution to Infrastructure Sustainability

In this study, IBS application in infrastructure projects was explored through the

discovery of the drivers, the challenges, and the consideration factors of its application.

This sub-section discusses the IBS contribution to infrastructure sustainability. This

sub-section examines questions four, five, and six by identifying the attribute of IBS

and its potential to accommodate redevelopment towards sustainable infrastructure.

Table 5-8 presents the results of the panellists’ ratings of the IBS attributes that

contribute to infrastructure sustainability for both rounds of the Delphi survey. In

Round 1, two-thirds of the items reached early consensus. Three of those items

received absolute agreement: “cleaner construction site”, “minimal on-site wastage

and environment pollution”, and “optimisation in material and energy consumption”.

These attributes may be explained through the industrialisation of the construction

components. Meanwhile, eight items did not gain consensus in this round, and were

therefore included in Round 2 of Delphi survey.

In Round 2, three more items: “reduced design complexity”; “availability of

spare parts for future maintenance or modification purpose”, and “flexibility to

accommodate modification and expansion” reached consensus and achieved better

agreement. Therefore, the remaining five items were de-listed.

Table 5-8: Rating results for the sustainability attributes of IBS application in infrastructure projects

Items IQR



ROUND 1

1 Cleaner construction site 1.0 0% 100% YES

2 Minimal on-site wastage and environment pollution 1.0 0% 100% YES

3 Simplified construction activities 1.0 0% 93% YES

4 Precision in component size and dimension 1.0 7% 80% YES

5 Shorter construction timeframe 1.0 7% 87% YES

6 Optimisation in material and energy consumption 1.0 0% 100% YES

7 Better quality control 1.0 0% 80% YES

8 Cost savings by providing economic of scale 1.0 13% 80% YES

9 Efficient handling and assembly operation 0.0 0% 87% YES

10 Safer and more convenient working environment 2.0 7% 73% NO

11 Minimal nuisance to public 0.0 7% 87% YES

12 Reduced design complexity 2.0 7% 60% NO

13 Low possibility of material or components outage 1.0 7% 60% YES


Items IQR



14 Minimal errors and mistakes due to component aggregation

1.0 7% 67% YES

15 Recycle and reuse options through dismantle ability 1.0 0% 53% NO

16 Simultaneous design work and components (or panels) production

2.0 20% 60% NO

17 Less carbon emission by reducing of material delivery trips

1.0 7% 60% YES

18 Effective coordination between stakeholder due to long-term commitment

1.0 13% 67% YES

19 Substitutability of operational and maintenance arrangement

1.0 13% 67% YES

20 Option for customisation 1.0 13% 60% YES

21 Minimal on-site risks 1.0 13% 53% NO

22 Availability of spareparts (e.g. panels, connectors, etc) for future maintenance or modification purpose

2.0 27% 47% NO

23 Cost savings on transportation of material 1.0 20% 33% NO

24 Flexibility to accommodate modification and expansion

2.0 33% 40% NO

ROUND 2

1 Safer and more convenient working environment 2.0 - 69% NO

2 Reduced design complexity 0.5 - 69% YES

3 Recycle and reuse options through dismantle ability 1.0 - 54% NO

4 Simultaneous design work and components (or panels) production

0.5 - 46% NO

5 Minimal on-site risks 1.0 - 46% NO

6 Availability of spare parts (e.g., panels, connectors, etc) for future maintenance or modification purpose

1.0 - 77% YES

7 Cost savings on transportation of material 1.5 - 54% NO

8 Flexibility to accommodate modification and expansion

1.0 - 77% YES

Nine items were rated above 4.0, while 3.38 was the lowest rating for the

remaining items. Table 5-9 presents the mean ratings of the items for the IBS attributes

by panellist subgroups. As shown, the rating for the top three items was approximately

consistent among the panellists’ subgroups. For the items “precision in component size

and dimension” and “cost savings by providing economic of scale”, it was noticeable

that the consultant subgroup ranked these items in contrast to the other four groups.

Similarly, the consultant subgroup gave the item “effective coordination between

stakeholder due to long-term commitment” a high rating, while the other subgroups

did not. Even though this significant contrast seemed to influence the overall rank for

these items, the variance of perspective between the subgroups was respectable, as

they held different positions in the construction industry.


Table 5-9: Mean ratings for the sustainability attributes of IBS by panellist subgroup

Items

All panellist



Cleaner construction site 4.53 1 4.33 2 4.50 1 4.75 1 4.50 5 4.50 4

Minimal on-site wastage and environment pollution

4.47 2 4.33 2 4.25 2 4.50 2 5.00 1 4.50 4

Simplified construction activities 4.47 2 4.67 1 4.00 3 4.50 2 5.00 1 4.50 4

Precision in component size and dimension 4.27 4 4.33 2 3.75 7 4.00 12 5.00 1 5.00 1

Optimisation in material and energy consumption

4.27 4 4.33 2 4.00 3 4.50 2 4.50 5 4.00 10

Shorter construction timeframe 4.27 4 4.33 2 3.50 9 4.50 2 4.50 5 5.00 1

Better quality control 4.13 7 4.00 9 4.00 3 4.25 9 4.50 5 4.00 10

Cost savings by providing economic of scale

4.07 8 4.33 2 4.00 3 3.00 19 5.00 1 5.00 1

Efficient handling and assembly operation 4.07 8 3.67 11 3.75 7 4.50 2 4.50 5 4.00 10

Minimal nuisance to public 3.93 10 3.67 11 3.50 9 4.50 2 4.00 11 4.00 10

Reduced design complexity 3.92 11 4.00 9 3.33 12 4.00 12 4.00 11 4.50 4

Minimal errors and mistakes due to component aggregation

3.73 12 3.67 11 3.50 9 3.75 15 4.00 11 4.00 10

Low possibility of material or components outage

3.73 12 3.33 15 3.25 13 4.25 9 3.50 17 4.50 4

Less carbon emission by reducing of material delivery trips

3.67 14 4.33 2 3.00 14 3.75 15 4.00 11 3.50 18

Effective coordination between stakeholder due to long-term commitment

3.60 15 3.33 15 3.00 14 4.50 2 3.00 19 4.00 10

Substitutability of operational and maintenance arrangement

3.60 15 3.33 15 3.00 14 4.25 9 4.00 11 3.50 18

Availability of spare parts (e.g., panels, connectors, etc) for future maintenance or modification purpose

3.54 17 3.00 19 2.33 18 4.00 12 4.00 11 4.50 4

Option for customisation 3.53 18 3.33 15 3.00 14 3.50 18 4.50 5 4.00 10

Flexibility to accommodate modification and expansion

3.38 19 3.50 14 2.33 18 3.75 15 3.50 17 4.00 10

Based on the literature in this study, the researcher found that certain criteria for

IBS had benefits for future modification or adaptation. Examining the bigger picture

for future redevelopment potential, the two subsequent questions aimed to identify to

what extent the IBS is relevant to the criteria of adaptability and to accommodate

changes.

Table 5-10 presents the six adaptability criteria that were rated, and these

included “versatile”, “adjustable”, “refitable”, “moveable”, “scalable”, and

“convertible”. The adaptability criteria of IBS were agreed upon by the panellists. All

criteria reached early consensus in Round 1, with the majority having more than 80%

agreement in relation to being relevant.


Table 5-10: Rating results for IBS adaptability criteria in facilitating infrastructure redevelopment



ROUND 1

1 Versatile 1.00 0% 93% YES

2 Adjustable 1.00 7% 87% YES

3 Refitable 1.00 0% 93% YES

4 Moveable 1.00 0% 80% YES

5 Scalable 1.00 0% 87% YES

6 Convertible 1.00 13% 67% YES

Table 5-11 provides the distribution of the panellists’ perception by subgroups.

The results show that “versatile” was the feature that the panellists deemed most

adaptable in regards to IBS (mean: 4.40), followed by “adjustable”, “refitable”,

“scalable”, “moveable” and “convertible” (mean: 4.33, 4.33, 4.27, 4.27, and 3.73,

respectively). Overall, most of the criteria were relatively highly rated, with the

majority above 4.0, which indicates panellists’ tendency toward the higher side of the

five-point Likert-scale. However, it can be seen that manufacturer subgroup rated

“convertible” low, at 2.5. This shows that this subgroup disagreed that IBS was

convertible in facilitating future redevelopment.

Table 5-11: Mean ratings for the adaptability criteria by panellist subgroup

Items All panellist Clients Contractor Consultant Manufacturer Researcher


Versatile 4.40 1 5.00 1 4.00 3 4.50 1 4.50 1 4.00 6

Adjustable 4.33 2 5.00 1 3.75 4 4.25 4 4.00 2 5.00 1

Refitable 4.33 2 4.67 3 4.25 1 4.25 4 4.00 2 4.50 3

Scalable 4.27 4 4.67 3 3.75 4 4.50 1 4.00 2 4.50 3

Moveable 4.27 4 4.00 6 4.25 1 4.50 1 3.50 5 5.00 1

Convertible 3.73 6 4.33 5 3.25 6 4.00 6 2.50 6 4.50 3

In addition to the adaptability capacity of IBS, the researcher also determined to

what extent the panellists found the changeability criteria of IBS benefitted

infrastructure redevelopment. Five items related to IBS changeability were assessed in

Round 1 of the Delphi survey. Table 5-12 shows the achievement of consensus gained

by those items in the two rounds of the survey. All items achieved at least 60%

agreement by the panellists in Round 1. However, the items “change of size” and

“change of space” had high variability in ratings, with an IQR of >1.0 meaning they


required a second assessment. Following the Round 2 survey, both items achieved

more condensed ratings, which reduced the IQR value. Thus, all items for this question

achieved consensus at the completion of the Delphi survey.

Table 5-12: Rating results for IBS changeability criteria for infrastructure redevelopment



ROUND 1

1 Change of location (e.g., relocate, deconstruction) 1.0 7% 80% YES

2 Change of function (e.g., revitalise) 0.0 7% 80% YES

3 Change of size (e.g., expansion, extension) 2.0 13% 73% NO

4 Change of space (e.g., layout modification) 2.0 20% 60% NO

5 Change of performance (e.g., retrofit, refurbish, rehabilitate)

1.0 20% 67% YES

ROUND 2

1 Change of size (e.g., expansion, extension) 1.0 - 69% YES

2 Change of space (e.g., layout modification) 1.0 - 69% YES

The distribution of ratings by subgroups for the items relating to the

changeability criteria are presented in Table 5-13. The panellists most acknowledged

the capability of IBS to support potential relocation of infrastructure (mean: 4.00).

They also believed that IBS created benefits in facilitating changes of function, space,

size, and performance (mean: 3.80, 3.62, 3.62 and 3.60, respectively) for future

redevelopment of infrastructure. These ratings were quite low, scoring between 3.0 to

4.0. This may be explained by the fact that even though these items were feasible, the

panellists were not very sure about how this changeability would work in practical

terms.

Table 5-13: Mean ratings for the changeability criteria by panellist subgroup

Items All Clients Contractor Consultant Manufacturer Researcher


Change of location (e.g., relocate, deconstruction)

4.00 1 4.00 3 3.25 2 4.25 1 4.00 1 5.00 1

Change of function (e.g., revitalise)

3.80 2 3.67 4 3.50 1 4.00 2 4.00 1 4.00 3

Change of space (e.g., layout modification)

3.62 3 4.50 1 2.67 4 4.00 2 3.00 3 4.00 3

Change of size (e.g., expansion, extension)

3.62 3 4.50 1 2.67 4 4.00 2 3.00 3 4.00 3

Change of performance (e.g., retrofit, refurbish, rehabilitate)

3.60 5 3.67 4 3.25 2 3.75 5 3.00 3 4.50 2


5.3.3 IBS Optimisation Strategies for Infrastructure Redevelopment

In order to embrace the benefits and advantages of IBS application to the fullest,

the multiform of IBS capability that potentially contributes to the infrastructure

sustainability determined was discussed in the previous subsections. This includes the

identification of IBS attributes and the capacity to facilitate future redevelopment.

With those interests in mind, the redevelopment potential is now embedded as part of

the consideration in strategising the IBS application.

Table 5-14 presents the rating results obtained from Round 2 of the Delphi

survey to determine which items achieved consensus. In Round 1, 18 out of 22 feasible

strategies for optimising IBS application reached early consensus, with a majority

having more than 80% agreement. Four items were retained and contained in the

Round 2 Delphi survey to be re-rated. At the end of Round 2, two of the items achieved

consensus, both with 69% agreement and an IQR=1.0. The remaining items were

eliminated, even if their level of agreement had increased in this round.

Table 5-14: Rating results for IBS optimisation strategies for infrastructure redevelopment



ROUND 1

1 Engage contractor and supplier in the design process and incorporate their concerns

1.0 0% 100% YES

2 Establish mutual objectives and cooperation among stakeholders

1.0 0% 93% YES

3 Reduce the complexity of structural systems (e.g., Avoid multiple types of structural systems)

1.0 0% 93% YES

4 Retain all information on the building construction systems, as well as assembly and disassembly procedures

1.0 0% 87% YES

5 Provide access to all components (or panels) and connection points

1.0 0% 87% YES

6 Use lightweight material 1.0 0% 87% YES

7 Consider the capabilities to redevelop in the project planning and design

1.0 0% 80% YES

8 Avoid wet-trade connections 1.0 0% 80% YES

9 Use standard size and dimension of the components (or panels)

1.0 7% 87% YES

10 Provide permanent identification of components (or panels) and connections used

1.0 0% 87% YES

11 Engage with supplier for spare-part supply 1.0 0% 80% YES

12 Use non-structural components (or panels) for interior walls

1.0 0% 80% YES




13 Use standard, simple and low-tech construction technology (e.g. Using common tools and building practices)

1.0 7% 80% YES

14 Minimise number of components/panels (e.g., use fewer large components (or panels) rather than many small components (or panels))

2.0 7% 73% NO

15 Use modular wall panel systems 0.0 0% 87% YES

16 Adopt long-term procurement system which covers post-construction phase

2.0 0% 73% NO

17 Consider high reusable material (e.g,. steel) 0.0 0% 80% YES

18 Use common and standard connections 0.0 7% 87% YES

19 Disentangle utilities (mechanical, electrical and piping) systems from structure

1.0 7% 73% YES

20 Minimise different types of materials 1.0 7% 67% YES

21 Minimise number of fasteners (e.g., se fewer strong fasteners)

1.0 7% 53% NO

22 Over-design shear walls 1.0 13% 47% NO

ROUND 2

1 Minimise number of components/panels (e.g. use fewer large components (or panels) rather than many small components (or panels))

1.0 - 69% YES

2 Adopt long-term procurement system which covers post-construction phase

1.0 - 69% YES

3 Minimise number of fasteners (e.g., use fewer strong fasteners)

2.0 - 69% NO

4 Over-design shear walls 1.0 - 54% NO

The distribution of the mean ratings scored by the panellist subgroups is

presented in Table 5-15. According to the overall mean rating score, 15 items rated

above 4.0, while the remaining four items were between 3.62 to 3.87. The top three

important strategies for optimising IBS application for future redevelopment purposes

were “engage contractors and suppliers in the design process and incorporates their

concern”, “establish mutual objectives and cooperation among stakeholders”, and

“reduce the complexity of structural system”. Two of these strategies related to

stakeholder engagement during project delivery.

Generally, most of the items were rated consistently among the panellists’

subgroups. However, there were still some noticeable rating variations. The contractor

subgroup uniquely ranked “establish mutual objectives and cooperation among

stakeholders” 11th, which was in contrast to the other subgroups, who rated this item

in the top three ranks.


The contractor, consultant, and researcher subgroups ranked “use standard size

and dimension of the components (or panels)” as the 2nd and 3rd most important

strategies, while the remaining subgroups ranked this 17th and 18th. The consultant

subgroup also attributed the most important strategies to be “use standard, simple and

low-tech construction technology”, while the client, contractor, manufacturer, and

researcher subgroups ranked this 4th, 17th, 7th, and 12th, respectively. This may be

understandable, because as the designer, the consultants are the responsible for the

specification of components. Meanwhile, the more standardised components used, the

simpler work for the contractors as the builder.

For the five least important strategies, the manufacturer subgroup considered

“minimise different types of material” and “minimise number of components/panels”

to not be important, and rated them below than 3.0.

Table 5-15: Mean ratings for the optimisation strategies by panellist subgroup

Items

All panellist



Engage contractor and supplier in the design process and incorporate their concerns

4.60 1 4.67 1 4.75 1 4.50 3 5.00 1 4.00 12

Establish mutual objectives and cooperation among stakeholders 4.33 2 4.67 1 3.75 11 4.50 3 4.50 2 4.50 2

Reduce the complexity of structural systems (e.g., avoid multiple types of structural systems)

4.33 2 4.33 4 4.00 6 4.75 1 4.50 2 4.00 12

Retain all information on the building construction systems, as well as assembly and disassembly procedures

4.27 4 4.00 8 4.00 6 4.50 3 4.50 2 4.50 2

Provide access to all components (or panels) and connection points 4.27 4 4.00 8 4.50 2 4.50 3 4.00 7 4.00 12

Consider the capabilities to redevelop in the project planning and design 4.20 6 4.33 4 4.00 6 4.25 10 4.50 2 4.00 12

Use lightweight material 4.20 6 4.00 8 4.50 2 4.25 10 3.50 15 4.50 2

Use standard size and dimension of the components (or panels) 4.13 8 3.67 17 4.50 2 4.50 3 3.00 18 4.50 2

Avoid wet-trade connections 4.13 8 4.00 8 3.75 11 4.25 10 4.00 7 5.00 1

Provide permanent identification of components (or panels) and connections used

4.13 8 4.00 8 3.75 11 4.25 10 4.50 2 4.50 2

Engage with supplier for spare-part supply 4.13 8 4.00 8 4.00 6 4.50 3 4.00 7 4.00 12

Use modular wall panel systems 4.07 12 3.67 17 4.00 6 4.25 10 4.00 7 4.50 2

Use non-structural components (or panels) for interior walls 4.07 12 3.67 17 4.25 5 4.25 10 3.50 15 4.50 2

Use standard, simple and low-tech construction technology (e.g., using common tools and building practices)

4.07 12 4.33 4 3.25 17 4.75 1 4.00 7 4.00 12

Consider high reusable material (e.g. steel) 4.00 15 4.33 4 3.50 15 4.25 10 3.50 15 4.50 2


Items

All panellist



Use common and standard connections 3.87 16 3.67 17 3.25 17 4.25 10 4.00 7 4.50 2

Minimise different types of materials 3.80 17 4.00 8 3.75 11 4.50 3 2.50 19 3.50 19

Disentangle utilities (mechanical, electrical and piping) systems from structure 3.80 17 4.00 8 3.25 17 4.00 18 4.00 7 4.00 12

Adopt long-term procurement system which covers post-construction phase 3.62 19 4.00 8 3.33 16 3.75 20 4.00 7 3.00 20

Minimise number of components/panels (e.g.n use fewer large components (or panels) rather than many small components (or panels))

3.62 19 4.50 3 2.67 20 4.00 18 2.50 19 4.50 2

5.4 RELIABILITY OF THE DELPHI RESULTS

After the two rounds of the Delphi exercise, the aim of Delphi study was to

recognise the items where consensus was achieved. Regardless of the variability and

changes of opinion among the panellists, the Delphi study was designed to achieve

holistic agreement on the topic being examined. Two rounds of Delphi allowed the

panellists to review the relevancy of the collective responses in the earlier round, thus

enhancing the study’s construct validity. This practice is also known as a self-

validating mechanism, as the selection of panellists is based on their substantial

experience and expertise.

Correspondingly, the researcher examined the consistency of the panellists’

ratings for each round by analysing the interrater reliability. Interrater reliability

reflects the variation among the raters who measure the same subject (Koo & Li, 2016).

For this purpose, intra-class correlation coefficient (ICC) was used. ICC is an

inferential statistic that can be used when quantitative measurements are made on units

that are organised into groups. For this research, it describes how strongly the

responses of each panellist resembled each other. It is used to assess the consistency

or conformity of responses made by multiple panellists measuring a similar item.

Cicchetti (1994) suggested that ICC values less than 0.4 are indicative of poor

agreement, values between 0.4 and 0.59 indicate fair agreement, values between 0.60-

0.74 indicate good agreement, and values greater than 0.75 indicate excellent

agreement.

ICC estimates and their 95% confidence intervals were calculated based on

mean-rating (number of panellists=13), absolute-agreement, and a 2-way mixed-


effects model. Table 5-16 presents the ICC value for each round. Fair to good

agreement was found for both Delphi rounds, as the average measures of ICC were

0.619 and 0.623, respectively, with a 95% confidence interval, which indicates that the

Delphi’s findings are valid. Moreover, it is apparent that the ICC value increased from

Round 1 to Round 2. This shows that the agreement between the panellists improved

throughout the Delphi exercise. Thus, employing the two-round Delphi survey

successfully improved the agreement among panellists and the reliability of the results.

Table 5-16: ICC value for each round of Delphi survey.

Delphi Round ICC 95% Confident Interval

Lower bound Upper bound

Round 1 0.619 0.517 0.708

Round 2 0.623 0.521 0.711

5.5 SUMMARY

This chapter presented the results of the data analysis from the two rounds of the

Delphi survey. Specifically, it achieved its first objective, which was to verify the

preliminary findings from the interviews and literature. In addition, the Delphi results

also addressed the relevant and critical items relating to the consideration factors for

IBS application, the drivers and challenges of its implementation, the attributes that

contribute to infrastructure sustainability, and its potential to facilitate future

redevelopment.

The panellists who participated in this research had diverse professional

backgrounds with relative academic achievement and years of work experience in the

relevant field. They worked for different types of construction firms and several had

decision-making roles in their profession. Hence, their valuable inputs resulted in

holistic and reliable outcomes representing the Malaysian context.

Overall, based on pre-established items and after two successive rounds of

reassessing the rating scores, the panellists agreed that 75% of the 128 items were

relevant to the particular questions. Of these, 66 were highly rated, with a mean rating

of at least 4.0.

The panellists agreed on most of the consideration factors relating to IBS

application in infrastructure projects. There was absolute agreement for three factors,


which included “specification of designed components or panels”, “repetitiveness of

structural component design”, and “repetitiveness of architectural component design

and features”. Project cost was another factor with high ratings; however, consensus

was only reached in the second round.

With regards to drivers and challenges, drivers proved to be more outstanding

than challenges. The majority of challenges achieved late agreement in Round 2, while

half of the drivers reached early consensus in Round 1. Fifteen of the drivers were

highly rated, but only four for the challenges. The five-top rated IBS drivers were

“speed up on-site construction activities”, “reduce dependency on manpower”,

“simplify construction activities”, “reduce wastage” and “produce better construction

quality”. Meanwhile, the three most significant challenges were “uneconomic for

small-scale project”, “lack of experience”, and “high capital investment”.

Nine IBS attributes contributing to infrastructure sustainability were highly

rated, with some of these attributes also corresponding to the drivers. This may be

because several of the drivers of IBS application relate to the contributions towards

infrastructure sustainability, which may be beneficial for determining better strategies

to enhance and optimise IBS application.

The capacity of IBS in relation to the various dimensions of changes and

adaptation were also surveyed to determine the potential for future redevelopment.

These capabilities could be incorporated in strategic delivery of IBS implementation,

to compliment the 20 optimisation strategies that reached consensus in the Delphi

study.

The intra-class correlation (ICC) was then used to examine the inter-rater

reliability used to assess the consistency and conformity of the panellists’ responses.

As a result, the ICC value for both rounds of the Delphi survey was found to satisfy

absolute agreement. Moreover, the ICC value for Round 2 increased from the

preceding round, thus demonstrating that the Delphi survey successfully improved

agreement amongst the panellists and the reliability of the results.

Finally, these results were then used in subsequent research work to map

strategic actions relating to the guidelines, as discussed in the following chapter.

Chapter 6: Discussion 183

Chapter 6: Discussion

6.1 INTRODUCTION

This chapter further triangulates the results of the interviews (reported in Chapter

4:), the Delphi study (Chapter 5:), and theories and discussions obtained from the

literature review (Chapter 2:). These findings were then synthesised and integrated to

establish a comprehensive insight and to design a theoretical framework for IBS

application in infrastructure projects that includes future redevelopment consideration.

The development of this framework aims to assist with producing more sustainable

infrastructure through the optimisation of IBS application.

This chapter is divided into five main sections to respond to each of the research

questions. Section 6.2 presents an overview of the stakeholders’ understanding of IBS

and their perception of its application in infrastructure projects. It also discusses the

aspects under consideration for the infrastructure projects to undertake IBS

application, and the drivers and the challenges. Section 6.3 discusses the extent of IBS

contribution to the sustainability of infrastructure development, while Section 6.4

explains how the IBS application could promote the redevelopment of built

infrastructures. Section 6.5 then presents the strategies for IBS application in

infrastructure projects, including redevelopment consideration. Section 6.6 discusses

the developed framework for a sustainable IBS that is deliverable for infrastructure

projects. Finally, Section 6.7 provides a summary of the chapter.

6.2 IBS APPLICATION IN INFRASTRUCTURE PROJECTS

This section discusses stakeholder perceptions, consideration factors, and the

drivers and challenges of IBS application in infrastructure projects in Malaysia.

6.2.1 Perception of IBS

The interviewees described IBS as a construction innovation. Innovations, such

as material development, design improvement, and installation technology, have

upgraded the IBS application to a higher level of construction efficiency. The

evolution of IBS application has progressed over the years. Moreover, wider

184 Chapter 6: Discussion

application of IBS has led other researchers to continuously study IBS performance

and potential and the opportunity for a better IBS delivery.

The interviews revealed that various stakeholders referred to IBS in many

different ways, such as prefabricated construction, modular systems, and off-site

construction. Regardless of the terminology used, these terms are consistent with the

CIDB’s early definition in the IBS Roadmap 2003-2010:

The industrialised building system (IBS) is a construction process that

utilises techniques, products, components or building systems which

involve prefabricated components and on-site installation. (CIDB,

2003)

Most of the interviewees related IBS with the industrialisation procedure. As the

word “industrialised” is embedded in the terminology, this clearly explains what the

IBS concept is meant to be. The panellists associated IBS with other words, such as

factory, manufacturing, precast, prefabricated, ready-made, tailor-made, erection,

installation and mechanisation, which shows their common understanding that the

concept of industrialisation in IBS relates to industrialising the construction process

rather than just manufacturing the products. The process involves three main elements:

component production, delivery, and installation.

Firstly, component production is the major phase in the industrialisation process.

It is carried out under a controlled environment, and is usually located away from the

construction project site (also known as off-site construction); while in some projects,

prefabricated components are produced in a casting yard located inside the project site.

However, both approaches eliminate cast in-situ activities. Factory-made components

are produced based on either standard or custom design. The precast manufacturers

compile the selection of standardised components with a range of preferred dimensions

in their product catalogues. Using automated production technology, the fabrication of

precast components is then repetitively produced. These components are then tested

for quality control and uniquely labelled. This systematic procedure assures optimal

production capacity is controlled (Khalili & Chua, 2014).

The second element is the transportation of the components to the construction

site to satisfy installation demands. The delivery of components is comprehensively

scheduled to arrive on-site in the correct amount and sequence so as not to overload


the limited space of the project site. Depending on the construction site location and

condition, scheduling and regulation may be required as part of the logistics planning

(Antunes & Gonzalez, 2015). Following the component delivery, installation then

takes place by means of hoisting, erecting, and assembling the components to build

the structure using automation and mechanisation approaches. Depending on the

materials used, component assembly may require an appropriately designated

mechanism of joint connection to complete the structure. From the interviews, it was

found that most connection systems between the precast concrete components involve

a wet-trade connection. The component production, delivery, and installation

eliminate the issue of cast in-situ found in conventional construction methods.

On the other hand, one interviewee claimed that the word “building” used in the

term “IBS” possibly confuses the industry. IBS is usually associated with the

construction of multistorey buildings, such as residential buildings, commercial or

office buildings, and schools. This misconception of IBS implementation being limited

to building projects is occurring across the local industry, which is not surprising. This

may be due to the early years of IBS initiative, in 2005, when the Malaysian

Government promoted IBS usage through the mass construction of low-cost houses.

Moreover, all government building projects have been mandated to comply with at

least 50% of IBS applications since then (CIDB, 2005), and this increased to 70% in

2008 (CIDB, 2010). The focus is more towards multistorey building projects, as such

projects have high IBS potential due to the repetitive nature of production (CIDB,

2010). While the term “IBS” has been embraced by the CIDB, it does not specify the

types of construction projects to be involved.

The findings in Section 4.3.2 show that IBS has long been applied in

infrastructure projects. The application of an appropriate IBS system depends on the

type of components used and how the system is suited to that particular project type.

For example, prefabricated components, such as columns, beams, slabs, and roof

trusses have been used in many projects. The application of IBS is commonly

implemented in building-type infrastructures, such as schools, mosques, hospitals, fire

stations, airports, and rail depots. On the other hand, the interviewees were also aware

that IBS has also been employed in other system applications, such as structural

steelwork, reinforced and post-tensioned concrete, prefabricated timber structures, and

structural glazing in different types of infrastructure projects such as bridges, train


tracks, roads and drainage, piers and viaducts, and tunnels. This is consistent with the

CIDB (2010), which stated that IBS was a natural choice for these type of projects.

6.2.2 Consideration Factors of IBS Implementation in Infrastructure Projects

In addressing the second research question, the researcher firstly recognised the

required factors in consideration of IBS implementation in infrastructure projects.

Though many previous studies (Abd. Rahman & Omar, 2006; Bari, Abdullah, et al.,

2012; N Blismas et al., 2006; Kamarul Anuar Mohamad Kamar et al., 2009; Larsson

et al., 2014) have investigated the drivers and challenges of IBS application, these

studies did not examine specific project types, particularly in relation to infrastructure

projects. For this reason, this research investigated the valid drivers and challenges for

IBS application within this research context. The identified drivers and challenges

were used as the “road map” for the establishment of continuous improvement

strategies and proposal of practical opportunities. Stakeholder roles could therefore be

channelled towards the concerns that require the most attention (Chileshe,

Rameezdeen, & Hosseini, 2016).

Based on the research findings, the Delphi panellists determined that four

dimensions with in the 17 consideration factors were relevant and significant.

According to the panellists, design requirements requires the most attention, followed

by policy, project characteristics, and industrial readiness, as shown in Figure 6-1.

Each of the categories is further discussed in the subsequent sections.

Figure 6-1: Priority of consideration factors for IBS adoption

Design Requirement

The first dimension is described as “design requirements”. It concerns the

selection of the appropriate IBS system, the specification of the designed components,

application of the standardised structural components, application of standardised


architectural components, the repetitiveness of the structural component design, and

the repetitiveness of the architectural component design and features. The Delphi study

found that this factor was the most prioritised by the consultants, manufacturers, and

researchers. This would be seen as reasonable for consultants, as they are responsible

for determining and realising a project’s design concepts, while design requirements

challenge the capability and capacity of manufacturers.

The two main components that require an integrative design process to meet a

project’s objective are architectural design and structural design. Architectural design

deals with the design of spaces and the layout for a particular function that creates

aesthetics, while structural design deals with the study of the internal structure that

keeps the structure safe, durable, strong, and economic. The component manufacturer

usually produces a variety of standard components with a range of preferred

dimensions, shapes, and materials for each type of component. Therefore, the

consultant is advised to obtain this information from the supplier regarding standard

and bespoke solutions (Elliott, 2017b). For that purpose, CITP initiated the publication

of IBS catalogues, with cooperation and coordination of multiple IBS suppliers to

further enhance IBS adoption by increasing accessibility of information on IBS

components specifications. It is seen as more convenient if the designers consider

using standard components, more so if the same components are used repetitively in

other structural segments. This not only reduces costs, as standard components are

produced in larger scales, it also simplifies the process of supply and installation. The

complexity and mishandling of managing the variability of component sizes can,

therefore, be avoided.

However, this does not mean that exclusive design specification renders IBS

application impossible. Standardisation does not necessarily restrain architectural

freedom. However, it is important to realise that it will incur an extra cost due to

alterations to the mould and provisional performance tests. The higher the degree of

uniqueness in the products, the higher production cost will generally be (Jonsson &

Rudberg, 2014). That is why architects must consider the limitations of their structural

design. Yuan et al. (2018) recommend the designers to fully consider the concept of

design for manufacture and assembly (DfMA) on their design to allow good

manufacturability and assemblability of the construction components. The utilisation

of standardised components could then be maximised without inflating the overall


cost. Consequently, the utilisation of multi-identical components creates repetition of

procedures during the installation process. Antunes and Gonzalez (2015) found that

repetitiveness provides the opportunity for improvement of processes.

IBS applications are not solely about the use of prefabricated concrete, they also

include steel framing systems, prefabricated timber framing systems, steel formwork

systems, and block work systems. Choosing an appropriate system selection based on

the type of built structure and loading requirement is essential to ensuring the

effectiveness and constructability of IBS. For example, steel or timber framing systems

are more appropriate for roof trusses, in contrast to precast concrete systems. For

longer spanned beams, a steel structure is a better choice than bulky concrete

structures. A steel structure design is simpler for the contractor to resolve by

themselves, as standard serial sizes of components and connection types are market-

ready. In contrast, a precast structure has to be designed for manufacture. Elliott

(2017b) also pointed out that precast design solutions are highly dependent on the

particular manufacturing and construction approach. It is therefore essential to involve

the manufacturer and supplier to ensure the design requirements suit the manufacturing

capability (Nasrun et al., 2011).


The second dimension concerns project size, the type of infrastructure project,

the location of the project site, and the cost of the project, which are collectively

described as “project characteristics”. In the case of IBS implementation, the size of

the project influences the economy of scale for product industrialisation. The larger

the scale of the project, the larger the number of components required, which aligns

with IBS application. The mass volume of component production will spread out the

massive investment in technology, manpower, and production facility to achieve an

economic state in IBS implementation (Ahmad, Mohammad, Musa, & Yusof, 2015).

Whereby, the standardisation of product dimension and repetitiveness of design allows

for a high degree of productivity in the production process. Elliott (2017b) suggested

a minimum project size within a range of 1,500 to 2,500m2 floor area, including 500

to 750m linear components (beam, columns) and/or 1,000 to 2,500m2 of façade and

wall panels to benefit from the efficiency of manufacture and construction. For small-

scale projects, utilisation of market-ready standardised components would be a better

option than custom design to achieve cost-effectiveness.


The classification of IBS in Malaysia is comprised of several types of systems

and a range of material selection. The suitability of the adoption depends on the nature

of the project. The project type can determine the degree of IBS adoption (Smith,

2011). The contractors strongly believed that type of infrastructure project leads to IBS

application. However, the GoM as a key client of Malaysian construction industry has

provided leadership in obtaining and standardising the design, specifications and

materials of IBS components (CIDB, 2015). This, so far only applicable for limited

projects such as schools, hospitals, and governments offices. Most infrastructure

projects that are not classified as a “building” type are also likely to have long utilised

prefabricated components; for example, tunnel lining for tunnel projects, precast

segmental box girders for bridges, elevated roadways or railways, and culverts for

drainage and irrigation projects. Moreover, the requirement of post-tensioned and pre-

stressed for high-performance structures make IBS a more effective option. Perhaps,

with on-going research efforts, the similar practice can be propagated to other


Infrastructure project job sites are sometimes located in challenging areas, such

as in busy traffic areas, and are located away from production facilities, over water, or

adjacent to other built facilities. To some extent, these locations are possibly not

conducive to traditional practices, and therefore require a convenient method to

manage the particular challenges. For example, dense urban sites may require a fast-

track erection method to manage logistic constraints. It is also important to consider

the distance of manufacturing facilities from the project site. There is the possibility

that the cost of transportation and the intangible implication to the environment may

be greater than the savings of resources (Smith, 2011). Project players must

acknowledge these elements and evaluate the implication of IBS application to the

constructability, safety, and cost of the projects.

With regards to clients, the cost of the project is an essential criterion in

considering IBS applications is an infrastructure project. This is reasonable, as the

developer is mainly concerned with profit (Mao, Shen, Pan, & Ye, 2015). In the case

of mega-infrastructure projects, these usually incorporate aesthetical features and

possess specific functional characteristics. This may require specialist design options

or installation requirements that imply expensive expenditures. It is therefore crucial

to evaluate the project viability and feasibility by assessing the implications of IBS


application in terms of tangible and intangible costs (Howes & Robinson, 2005). For

projects in which cost is a major concern, utilisation of IBS has to be undertaken

intentionally, with very comprehensive planning (Smith, 2011).

Policy

The third dimension focuses on “policy”, which is associated with the

requirements of the project developer and the requirements of government policy. The

establishment of appropriate policies in the construction industry is used to improve

the efficiency and effectiveness of project delivery. Howes and Robinson (2005) stated

that the capability of a project to support and implement policies would improve the

level of services by providing significant influences on the level of coordination, and

financial and technical resources. The Malaysian Government, together with CIDB

introduced strategic plans and policies to promote IBS in the Malaysian construction

industry. For example, in CIMP 2006-2015, the promotion of IBS was highlighted

under Strategic Thrust 5: Innovate through R&D to adopt a new construction method

(CIDB, 2007). The IBS Roadmap 2003-2010 and IBS Roadmap 2011-2015 were

introduced to steer the IBS direction by addressing related issues and imposing

exceptional outcome of implementing IBS respectively (CIDB, 2003, 2010). From

2007 onwards, new incentives for IBS implementations were introduced (Hamid et al.,

2011). The latest, started in 2008, and is a levy exemption given to contractors who

use at least 70% of IBS components in government project development and 50% in

private projects. However, contractors for non-building types of infrastructure projects

do not receive the levy exemption, as it is only valid for building projects, though

probably that this policy requirement does not influence contractors in regards to IBS

application. Nevertheless, the launch of the policy has led to wider adoption of IBS.

The mean of IBS scores in government and private projects has achieved the target set

by IBS roadmap 2011-2015, together with the rise of CIDB-registered IBS

manufacturers from 70 in 2007 to 189 in 2014 (Abd Hamid et al., 2017).

The implementation and enforcement of government policy will not succeed

without the full support of the industry players. Project developers, as the money

spenders, hold an essential role in ensuring the success of IBS adoption. As many

infrastructure projects in Malaysia are procured with design-bid-build contracts, there

is a rational explanation that the client organisation controls the rules and regulations

of the design process. The organisations providing project funding have a supreme


authority in project decision making (Howes & Robinson, 2005). The client’s initiative

to set a pre-condition to include IBS adoption in project implementation leaves no

option for the builders and designers to use their own preferences. In fact, given that

IBS has a high potential for contribution towards sustainable construction, the

implementation will provide a great point for the Green Building Index, which is

recognition for a project that emphasises efficient resources and energy usage. Based

on past research, such recognition schemes have positive impacts relating to

convincing developers to adopt green practices (Heinzle, Ying Yip, & Yu Xing, 2013).

Therefore, these initiatives have become a prerequisite for project planning and

influence decision making.

Industrial Readiness

The final dimension is related to “industrial readiness” in regards to the

availability of local materials, appropriate technology, competent manufacturers or

suppliers, competent designers, and competent contractors. These elements represent

a measure of the extent to which the industry is prepared for and capable of optimising

the adoption of IBS. The competency of project player plays an important role in

delivering a successful project. The effectiveness and efficiency of IBS

implementation relies on the capability and capacity of the project executors to provide

their best services. This is consistent with Kamar et al. (2010), who found that

experienced and well-trained workers are an important requirement for successful IBS.

The transformation of a conventional system to IBS requires tremendous focus and

necessary structural changes in project execution. It is essential for designers,

contractors, and component manufacturers to have the necessary skills and knowledge

for successful delivery of IBS application, in particular in relation to infrastructure

projects. Their experience in implementing IBS is also a huge advantage, as

unexpected and unique disputes may occur, even though substantial planning is in

place. In order to fill the expected demand by the industry, CITP offers the

opportunities of comprehensive training and development for all class level of

industrtry players including establishment of up-to-date training modules, courses for

new technology and modern construction practice, apprentices and internships

programmes as well as train-the-trainer programmes with world class experts

(Construction Industry Development Board (CIDB), 2015).


The designers have the responsibility of conceptualising infrastructure projects.

The contractors and the manufacturers are responsible for materialising the physical

built infrastructure. Competency of one party must be accompanied by the capability

of the others to succeed. For example, across multiple types of infrastructure projects

that impose solitary project characteristics, the designer should have the ability to

adapt and respond to change (Kwofie, Adinyira, & Botchway, 2015). With the superior

construction technology used in IBS implementation, the contractors require

specialised skilled workers to replace foreign workers (Kamar et al., 2010). At the

same time, the suppliers, referred to as component manufacturers, are obliged to

supply a wide range of IBS products. This continuous demand pressures the suppliers

to increase the product's production capacity to meet the current market. In parallel, it

can be seen that the number of ISO certified manufacturers in Malaysia has risen over

the years (Abd Hamid et al., 2017). Consequently, the business continuity in producing

components will stimulate the need for improvement in product development (Lou &

Kamar, 2012) including advancements in product concepts, enhancements in

production planning and quality control, and re-strategizing of supply chain

management (C. D. Singh & Khamba, 2015). This situation indicates that every project

player has a significant commitment to the successful delivery of IBS implementation

in infrastructure projects.

Regardless of the readiness and maturity of the project stakeholders’ perception

towards IBS, the availability of resources, including local materials and appropriate

technology is becoming a significant concern for implementing IBS. In Malaysia, steel

and concrete are the most common materials for structures, as they are readily

available and affordable. However, the selection of different types of material

potentially makes way for greater innovative solutions. Smith (2011) acknowledged

that variances often determine how the material is harvested, processed, manufactured,

and installed. Special materials, such as high strength, self-compacting, and recyclable

concrete have distinct significance in IBS component production and performance

(Elliott, 2017a). For example, self-compacting concrete delivers high-quality rapid-

hardening to exploit the full benefits of off-site fabrication, while utilising recycled

concrete as aggregate replacement requires additional manufacturing processes and

machinery. It is crucial to ensure the availability of particular materials or facilities at

the early stage of the design phase, as this affects cost, not to mention possibly creating


supply-logistic complications. The extent of supplier capacities for IBS

implementation in a project needs to be guaranteed.

As a modern construction method, IBS application involves a higher technology

application, whether in the component production process or installation works. The

construction industry currently makes use of innovative information technology to

improve the productivity of IBS applications in design, production, and assembly

processes. For example, building information modelling (BIM) allows better

information integration of resources and materials, work scheduling, production, and

installation technology options, including the costs involved for each, allowing for

better collaboration across disciplines throughout the construction lifecycle.

Leopoldseder and Schachinger (2017) stated that BIM facilitates IBS application in

terms of efficiency, productivity, and quality towards better performance and

remaining competitive globally. Similarly, the high utilisation of technology through

mechanisation, automation, and robotics makes ease of assembly and installation

activities while eliminating labor-intensive works (Waris, Liew, Khamidi, & Idrus,

2014). Undeniably, the more advanced the technology complementing IBS adoption,

the more value that is added to the success and effectiveness of IBS implementation.

6.2.3 Drivers of IBS Adoption in Infrastructure Projects

A total of 29 drivers were retrieved from the combination of the interview

findings and the literature review. Following methodological validation, a total of 25

items under these categories were deemed to be relevant to the Malaysian construction

industry by construction practitioners and researchers using a Delphi study. Only 15

items were considered significant (mean ≥ 4.0) based on the Delphi analysis. The

relevant drivers for the IBS application in infrastructure projects kept under the

established categories were: productivity, quality, environmental, safety and health,

constructability and design, cost, as well as policy and requirement. Each is discussed

further in the below sub-sections.

Improving construction productivity

The Delphi study analysis found that productivity was the most important driver

of IBS application in infrastructure projects. Productivity is one of the measurements

used for performance assessment of construction projects by investigating the

efficiency of project execution. Productivity is measured in terms of the rate of output


over the utilisation of labour, equipment, and material (Naoum, 2016). IBS simplifies

construction activities by breaking down the construction process into several

separable locations. This allows simultaneous site preparation work and component

production. This is in line with the CITP’s target to multiply the production rate in the

Malaysian construction industry (CIDB, 2015). Moreover, in manufacturing

environments, systemised parallel activities and operations lead to higher productivity

(Kamali & Hewage, 2016). Component production commonly operates inside, thus

being protected from potential interruptions arising due to unexpected weather

conditions. There is no risk of damage to the building materials and loss of job rhythm

of the construction workers caused by wet or extreme temperatures, whereas both of

these concerns are found to negatively influence construction productivity (Durdyev

& Ismail, 2016). A large proportion of construction workforce is low-skilled labour

(CIDB, 2015). Defects due to poor workmanship of an unskilled workforce and

underperforming labours may require extensive rework and result in low productivity

(Durdyev & Ismail, 2016). Therefore, the employment of machinery for component

production could reduce the dependency on manpower in IBS application, thus

reducing human-made defects. In addition, construction supervision could be

optimised by up to 19% by moving on-site works to the manufacturing floor (Abd

Hamid et al., 2017). At the same time, through mechanisation and industrialisation in

IBS application, the Malaysian construction sector would no longer rely heavily on

foreign manpower (Abd Hamid et al., 2017).

Upgrading the quality of final product

Most interviewees believed that IBS is preferred for implementation due to

quality performance. This was consistent with CITP that encourages the adoption of

modern method of construction to achieve higher quality score (CIDB, 2015). The

manufacturing process assures the production of components fabricated according to

design specifications. The accuracy of the instruments and machinery used in the

factory promises better consistency of product quality. Boyd et al. (2013) found that

establishment of robotic systems in the assembly-line allows for close tolerances,

predictability, and consistency based on a grid design. In addition, quality is measured

not only by physical appearance, but the extent of the structural strength of each

component. Component testing in a factory allows for better control of safety factors

and quality conformance. For example, temperature controlled curing ensures that the


quality of the precast component is better than concrete cast in-situ (MIDF, 2014).

Moreover, the factory also enables new and advanced materials and processes to be

adopted and tested, which is not practical in on-site construction (Nick Blismas &

Wakefield, 2009). Meanwhile, the early detection of anomalies during quality control

in the factory prevents interruption in the on-site building process. This then ensures

that assembly progresses according to schedule, without interruption due to component

defect issues.

Preserving the environment

Reducing the negative impact to the environment is a major concern for the

Malaysian construction industry. With an increasing demand for major infrastructure

projects in Malaysia, such as a rail transit system, highways, and commercial

buildings, a large amount of construction waste is being produced. Ecological

awareness is critical to ensure that the progress of infrastructure development does not

increase the atmospheric burden (Boyle et al., 2010). Minimisation of waste generation

was raised by several interviewees, in line with growing academic interest relating to

IBS with regards to environmental concerns (Dong & Ng, 2015; Jaillon et al., 2009;

Lachimpadi et al., 2012; Yunus & Yang, 2014). IBS removes labour-intensive

activities, such as steel bending, formwork fabrication, and in-situ concreting. No

formwork is used, meaning that no timber or plywood is wasted. It is also important

to note that IBS eliminates the need for temporary structures, such as scaffolding,

packaging waste, and temporary support for material handling and hoarding. These

activities profoundly contribute to waste generation at the construction site (Bari,

Abdullah, et al., 2012). In addition, the Delphi panellists were in high agreement that

IBS can reduce energy consumption and emissions. This aligns with Quale et al.'s

(2012) finding that energy expenditure for component production at the factory lowers

excessive energy for the fuel and electricity consumed by appliances and machinery

for conventional construction. Furthermore, the ability of IBS to improve recyclability

advances energy conservation. For example, utilisation of recycled steel conserves

approximately 70% of production energy and a minimum of a building’s initial

embodied energy (T. Y. Chen, Burnett, & Chau, 2001). The efficient use of resources

and the recoverability of material leftovers contributes greatly to the conservation of

the environment. Alongside, this was corresponding to the CITP’s aspiration to

promote Malaysian infrastructure projects to be more environmentally sustainable.


Promoting better safety and health practice

While IBS’s ability to minimise adverse impacts on the environment was readily

acknowledged by the interviewees, this also applied to the surroundings of the

construction site. Most infrastructure projects are located in urban areas or within high

traffic areas. The impact of health and safety for such project sites not only relates to

construction workers, but also the neighbourhood community. IBS provides neater and

safer working environments with minimal dormant material and machinery. Moreover,

transferring the in-situ casting to a more systemised manufacturing condition offers

better control of hazardous environments, and as stated by one interviewee:

“...removes all kind of unnecessary things, [and] could resolve the 3Ds

of [the] construction label, which is dirty, difficult and dangerous”

[P17]

Construction works must manage the perception of 3D jobs, or jobs considered

dirty, difficult, and dangerous (N. M. Salleh, Mamter, Lop, Mohd Kamar, & Mohamad

Hamdan, 2014). This pressure reveals IBS as an appropriate solution to lift the

standard of the local construction industry. Established production plants have

standard operational procedures equipped with the occupational health and safety

practices. This offers a better working environment to attract locals working in the

manufacturing industry, rather than relying on foreign workers at the construction site.

Accommodating constructability and design

Constructability is an important consideration in project implementation. For

infrastructure projects, constructability is defined as the optimum use of construction

knowledge and experience throughout the project life cycle to achieve the overall

project objectives (Saghatforoush, 2014). At the planning stage, IBS application

provides an easier assessment of the costs-benefits analysis, as the potential for

unexpected consequences is considered low. In terms of design, IBS increases

customisation options for special and complex design requirements, including the

utilisation of additives or the substitution of another kind of material. For example,

utilisation of steel structures might be a better option instead of bulky-long spans of

concrete structures. During component assembly, IBS also lessens installation issues,

such as difficult elevation or restricted work areas due to adjacent structures or those

that are over the water. IBS manages to incorporate new design aesthetics of a variety

of shapes, finishes, and high quality (Azman, Ahamad, & Hilmi, 2012). This is very


beneficial for infrastructure projects, because they are generally associated with

aesthetic features and innovative and sophisticated designs (Howes & Robinson,

2005).

Optimising project cost

Overall, cost factors are regarded as the driving force for IBS application. Even

though IBS can optimise material consumption through product industrialisation and

mass production, most of the Delphi panellists were unsure whether the application of

IBS could reduce construction costs. This may be due to some financial challenges

depending on the project’s size (discussed further in Section 6.2.4). However, looking

at the broader scope, the panellists agreed with the potential of IBS for reducing the

life cycle cost. Life cycle costs not only consist of the initial construction costs, but

also includes costs due to the design, operation, inspection, maintenance, repair, and

damage consequences along the structure’s lifetime (Frangopol & Liu, 2007). As IBS

was perceived as delivering a good quality component, this may lessen the post-

construction costs in the long term. Throughout the life cycle phase, tangible and

intangible costs are predictably measured, as IBS is not significantly affected by

uncontrolled risks due to workmanship and weather conditions. In this case, IBS offers

cost certainty and allows for comprehensive budget planning. On the other hand, the

shorter construction period allows for a quicker return on investment by clients, which

in turn, helps other stakeholders to gain early payment from the clients.

Complying with policy and regulation

The Malaysian Government mandated the implementation of IBS for

government building construction projects in 2005, and this has risen from a target of

at least 50% to 70% since 2008 (Hamid et al., 2011). IBS application has since not

only been used for government projects, it has also been implemented for private

projects. This factor has greatly driven the progression of IBS application in the

Malaysian construction industry. In recognition of the industry's response, a levy

exemption was granted to IBS adopters to further promote IBS adoption. However, it

is important to realise that this advantage is only valid for building construction

projects, other civil structures, such as bridges, tunnels, dams, viaducts, and drains are

not subject to the exception. On the other hand, the adoption of IBS in Malaysia is

client-driven. In response to this, project developers must take the initiative to establish

their own requirements for designers and builders to promote a higher uptake of IBS


application. Consequently, CITP recommends the Public Work Department, a key

client for most government-linked projects in Malaysia, establish a requirement for

IBS incorporation into Pre-Approved Plans to support the policy implementation

(CIDB, 2015).

6.2.4 Challenges of IBS Application in Infrastructure Projects

Despite acknowledging IBS application in infrastructure projects, the research

participants stated that there were common barriers to implementing IBS. The existing

barriers indicated problems experienced by industry practitioners when dealing with

IBS application. Among a total of 23 factors retrieved from the interviews and

potential barriers extracted from the literature, 16 factors reached consensus as being

relevant. Only four were considered significant (mean ≥ 4.0): “a high capital

investment”, “uneconomic for small-scale projects”, “lack of experience”, and “highly

restrictive construction tolerances”. Two of these are cost-related challenges, which is

consistent with the panellists’ ratings as the most prevalent challenges. Clients and

consultants were mostly concerned with lacking experience, while contractors and

manufacturers found that IBS was uneconomic for small-scale projects. All of the

relevant challenges rated by the participants were re-categorised and referred to

discrepancy during project planning, cost-related issues, and site constraints, as well

as immature industry capacity. These are further discussed in the following sections.

Discrepancy during project planning

Ideally, the implementation of IBS should be taken into consideration at the start

of project initiation. This requires the involvement of all stakeholders to ensure that all

decision making in the process of designing, constructing, and managing the project

execution incorporates IBS consideration. The effectiveness and efficiency of IBS

applications will not be achievable with inappropriate procurement practices. For

example, contractors face cash flow issues because they need to spend a large deposits

upfront to the supplier, regardless of the payment delay by the clients. Responding to

this, CITP recommends the separation of IBS procurement from the main contract to

remove the burden of financial liquidity of the contractors (CIDB, 2015). On the other

hand, in a local scenario, the supplier or product manufacturer is isolated in the project

planning phase until the tender stage of the construction supply chain (Kamar et al.,

2010), which means that unforeseen difficulties outside the designers’ perspective are

not considered earlier on. Inconsistent objectives between the architect and engineer


in the structural and architectural design principal make IBS application more

challenging. Moreover, the form and layout of infrastructure associated with complex

and aesthetic features challenge the designers to adopt IBS application. Geometrical

designs may need to be rationalised for more effective use of IBS (Smith, 2011).

Selfishness and intolerant attitudes between stakeholders makes this more

complicated. Poor cooperation among stakeholders ranked lowest in the Delphi study,

indicating significant room for improvement in this area. Moreover, the accuracy of

design configuration is very important, as it affects the workability of installation

during the assembly process. Once the production process begins, further design

changes are not expected. Even a small change can affect the whole construction

phase. An interruption in the manufacturing process due to design adjustment can have

a severe impact on production planning, where production of components from other

construction projects is also scheduled at the same time (Kamar et al., 2010). This

requires extensive work and time to restructure the entire project scheduling to ensure

component manufacturing and delivery processes do not result in cost and time

overrun. IBS application therefore requires longer lead times for comprehensive

project planning and design processes.

Cost-related issues and site constraint

Based on the findings from the Delphi study, cost factors are the biggest

challenges to implementing IBS. The use of IBS requires a high capital investment to

establish component production facility. The manufacturer provides enormous capital

for initial start-up, including the cost of purchasing machines, the prefabrication yard,

raw materials, moulds, foreign technology transfer, and wages of skilled worker during

the setting up process (Kamar et al., 2010; Rahman, 2014). Due to this expensive

capital, IBS application is not economical for small-scale projects. The production cost

per unit is higher if the component order is for small quantities (Y. Pan, Wong, & Hui,

2011). As a component producer, the manufacturers are the most affected by this

challenge. This is consistent with the Delphi findings that showed that manufacturers

and contractors considered this to be the most critical challenge. IBS manufacturers

are normally required to advance up to 75% of the capital to manufacture the

components (Abd Hamid et al., 2017). This requires sufficient financial backup for the

massive initial spending. For this reason, small contractors prefer to use conventional

construction techniques for such projects. Moreover, due to the abundance of cheap


foreign labour on the market, conventional practice is preferable. Malaysian

contractors do not pay for skills, relying instead on low cost-resources to generate

profits (MIDF, 2014). However, over a long period, the tangible and intangible

economic benefits throughout a whole project life cycle can offset the capital

investment. On the other hand, an increase in costs in IBS implementation is attributed

to the intensive expenditure on component transportation and delivery, especially for

infrastructure design that involves oversized components or complex features.

Furthermore, it is more challenging if the location of the project is remote from the

manufacturing facility. It is therefore important to distinguish between conducive and

restrictive location factors, as there are different considerations for each type of

infrastructure (Howes & Robinson, 2005).

Immature industry capacity

While the effort to promote IBS applications began in the last decade, there is

still pessimism and scepticism around this method. Bad impressions have been caused

by underperformance, such as low quality of buildings, leakage, abandoned projects,

and monotonic architectural appearances (Kamar et al., 2010). Additionally, some

stakeholders, especially contractors, are too comfortable with traditional methods,

causing them to be reluctant to become involved with this new venture. Undoubtedly,

most stakeholders have knowledge and awareness of the IBS’s benefits. The Delphi

findings show that clients and consultants strongly believed that lacking successful

experience and involvement caused stakeholders to be hesitant to make changes. This

is likely because they wish to avoid unexpected risks. The tendency to self-enhance

makes decision-makers reluctant to acknowledge the need for change (Audia & Brion,

2007). Moreover, experiencing failure on the first attempt may set them back for the

next attempt. However, as the project initiator, clients and consultants have the ability

to break a “chicken-egg dilemma” by firstly changing their attitude towards IBS

application. Optimisation of resource allocation for sustainable infrastructure should

ideally be driven by the planners and designers of the projects (Norris, 2012). Another

essential point is that the local industry does not have sufficient capacity for IBS

implementation. Even though there are 237 IBS companies in the Malaysian

construction industry, they just be able to fulfil 60% of the demand, with most of them

only able to produce certain housing construction components (CIDB, 2017b).

Insufficient technology and special equipment to provide an advanced production


facility is impeding the industry in dealing with the complexity of design features. In

addition, the IBS application guidelines that are currently available are only applicable

for certain types of systems. In practice, application of IBS in infrastructure projects

does not work in isolation, instead it is a hybrid system. Lack of comprehensive codes

and standards for such application leads to pessimism regarding the practicality and

workability of the IBS application as a whole.

6.2.5 Summary

Industry practitioners are aware of and understand the concept of IBS involved

component production, delivery, and installation, which replaces the major

activities of on-site construction. Although the implementation of IBS is often

associated with multi-storey buildings, it has long been used in infrastructure

projects. However, the undertaking of an IBS application requires several

considerations, including design requirements, policy, project characteristics,

and industrial readiness.

This study found a series of driving factors for IBS implementation in

infrastructure projects: productivity, quality, environment, constructability, and

design, cost, and policy and regulation. These factors can be used by each

stakeholder to identify and develop prospective opportunities to improve and

refine their role in promoting the use of IBS in the construction industry.

In addition to the many benefits of IBS, this study also provides insigt into

industry practitioner’s perceptions of the barriers to expanding the application of

IBS. These challenges are due to discrepancies during project planning, cost-

related issues, and site constraints, as well as an immature industry capacity.

Based on this subtle argument, the IBS consideration factors that were discussed

in Section 6.2.2 need to be addressed to improve the effectiveness of IBS

adoption.

Surprisingly, in terms of a number of significant factors, it seems that the drivers

offset the challenges of IBS application. This indicates a positive uptake of IBS

in infrastructure projects in Malaysia. For this reason, based on the logical links

within the above findings, this study demonstrates generic consideration factors

to manage in project appraisal, as illustrated in Figure 6-2. By featuring the

underlying drivers and challenges, strategies to upgrade IBS uptake can be better


formulated and articulated. However, it also important to note that the real

advantages of IBS can only be realised through a comprehensive understanding

of the attributes underpinning the process flow of IBS itself, while also

discovering solutions for the challenges to continuously motivate sectors of the

industry.


Fig

ure

6-2:

IB

S c

onsi

dera

tion

fact

ors,

dri

vers

and

cha

lleng

es f

or in

fras

truc

ture

pro

ject

app

rais

al


6.3 IBS DELIVERS SUSTAINABLE INFRASTRUCTURE

The fundamental aspects of project sustainability correspond to the three pillars

of sustainability principles: economic, social, and environment. This study examined

IBS's sustainability contribution from two perspectives. Firstly, by the performance of

its delivery process. Figure 6-2 shows the main elements of IBS sustainable

performance, comprised of cost effective, quality, productivity, health and safety,

waste minimisation, and adaptability. Every element does not necessarily adhere to a

single pillar, rather they contribute to multiple pillars, either directly or indirectly.

Figure 6-3: The sustainable IBS performance across sustainability pillars

The second perspective was through the sustainable characteristics of IBS. Table

6-1 presents how sustainable IBS characteristics and IBS delivery performance are

influenced and corresponded to the each other. For example, product industrialisation

provides precision in component size and dimension. As a result, it can avoid rework

due to the poor workmanship, and therefore increase the productivity rate. In this

matrix, it was found that a particular IBS characteristic or a specific performance was

not necessarily attributed to one specific sustainability pillar. For example, the

flexibility of some of the IBS systems to accommodate future changes provides an

option for redevelopment instead of demolishing for new development. This saves the


consumption of fresh material and reduces the cost of major construction. These

provide associated sustainability benefits across the pillars. To provide a more

meaningful appreciation and understanding of the matrix, a cross-reference was made

based on the triple sustainability pillars and these are discussed in the following sub-

sections.


Tab

le 6

-1: C

ross

-con

stru

ct o

f su

stai

nabl

e IB

S a

ttrib

utes

.

IBS

Su

stai

nab

le D

eliv

ery

Per

form

ance

C

ost

Eff

ecti

ve

Qu

alit

y P

rod

uct

ivit

y S

afet

y &

Hea

lth

W

aste

Min

imis

atio

n

Ad

apta

bil

ity

IBS

Su

stai

nab

le

Ch

arac

teri

stic


Min

imal

nui

sanc

e to

pu

blic

P

rodu

ctio

n fa

cili

ties

are

rem

ote

from

the

publ

ic

and

unde

r a

cont

roll

ed

envi

ronm

ent.

Pub

lic

is n

ot

expo

sed

to c

onst

ruct

ion

haza

rds

(e.g

., du

st, n

oise

, tr

affi

c co

nges

tion

)

Cle

aner

con

stru

ctio

n si

te

O

n-si

te w

orke

rs h

ave

less

ex

posu

re to

haz

ards

ca

used

by

scat

tere

d ra

w

mat

eria

ls/l

efto

vers

.

Min

imal

on-

site

was

tage

an

d en

viro

nmen

tal

poll

utio

n

No/

less

dum

ping

cos

t

L

ess

was

te, l

ess

poll

utio

n

Les

s w

asta

ge o

f ra

w

mat

eria

l pre

serv

ing

natu

ral r

esou

rces

.

Bet

ter

qual

ity

cont

rol

F

acto

ry e

quip

ped

wit

h qu

alit

y as

sura

nce

for

the

cons

iste

ncy

of p

rodu

ct

qual

ity

Pre

cisi

on in

com

pone

nt

size

and

dim

ensi

on

M

echa

nise

d m

anuf

actu

ring

sys

tem

pr

ovid

es a

ccur

ate

mea

sure

men

t

A

void

rew

ork

due

to

wor

kman

ship

fau

lt,

ther

efor

e in

crea

se

prod

ucti

vity

rat

e

Opt

ion

for

cust

omis

atio

n

M

anuf

actu

ring

fac

ilit

ies

allo

w f

or c

usto

m d

esig

n by

usi

ng f

lexi

ble

mou

ld


Tab

le 6

-1 (

Con

tinu

ed)

IBS

Su

stai

nab

le D

eliv

ery

Per

form

ance

C

ost

Eff

ecti

ve

Qu

alit

y P

rod

uct

ivit

y S

afet

y &

Hea

lth

W

aste

Min

imis

atio

n

Ad

apta

bil

ity

IBS

Su

stai

nab

le

Ch

arac

teri

stic

Mass-production

Opt

imis

atio

n in

mat

eria

l an

d en

ergy

con

sum

ptio

n

H

igh

volu

me

prod

ucti

on

is lo

wer

ing

the

aver

age

of

the

tota

l cos

t and

ene

rgy

used

.

C

onsi

sten

t qua

lity

pr

oduc

t

U

sing

mec

hani

sati

on

tech

nolo

gy a

nd

tem

pera

ture

con

trol

, hig

h vo

lum

e pr

oduc

tion

at o

ne

tim

e lo

wer

ing

the

aver

age

of ti

me

cons

ume

per

unit

co

mpo

nent

P

rese

rvin

g na

tura

l re

sour

ces

of r

aw

mat

eria

ls

Cos

t sav

ings

by

prov

idin

g ec

onom

ic o

f sc

ale

H

igh

volu

me

prod

ucti

on

of c

usto

m d

esig

n co

mpo

nent

off

set t

he s

et-

up c

osts

Transport and assembly technique

Sim

plif

ied

cons

truc

tion

si

te

E

lim

inat

e un

nece

ssar

y co

st (

e.g.

, sca

ffol

ding

, pl

aste

ring

wor

k),

ther

efor

e el

imin

ate

unne

cess

ary

cost

s.

Req

uire

s sk

ille

d w

orke

rs

for

spec

iali

sed

wor

ks

R

educ

e on

-sit

e ri

sks

Les

s ca

rbon

em

issi

on b

y re

duci

ng o

f m

ater

ial

deli

very

trip

s

L

ess

fuel

con

sum

ptio

n,

redu

ce c

arbo

n em

issi

on

and

pres

ervi

ng n

atur

al

reso

urce

s

Fle

xibi

lity

to

acco

mm

odat

e m

odif

icat

ion

and

expa

nsio

n

R

edev

elop

men

t is

chea

per

than

re-

buil

d.

A

llow

for

red

evel

opm

ent

such

as

mod

ific

atio

n or

re

furb

ishm

ent i

nste

ad o

f di

spos

al/d

emol

ish.

D

isas

sem

ble

abil

ity

(e.g

., st

eel s

truc

ture

wit

hout

w

et c

onne

ctio

n) w

ould

si

mpl

ify

the

mod

ific

atio

n or

ren

ovat

ion

wor

ks.


Tab

le 6

-1 (

Con

tinue

d)

IBS

Su

stai

nab

le D

eliv

ery

Per

form

ance

C

ost

Eff

ecti

ve

Qu

alit

y P

rod

uct

ivit

y S

afet

y &

Hea

lth

W

aste

Min

imis

atio

n

Ad

apta

bil

ity

IBS

Su

stai

nab

le

Ch

arac

teri

stic

Structured planning and standardisation

Min

imal

err

ors

and

mis

take

s du

e to

co

mpo

nent

agg

rega

tion

L

ess

vari

ant o

f th

e co

mpo

nent

s,

redu

ce th

e co

mpl

exit

y of

sup

ply

chai

n fo

r de

live

ry. A

void

tim

e ov

erru

n du

e to

del

iver

y m

ista

kes.

Red

uced

des

ign

com

plex

ity

E

mpl

oym

ent o

f st

anda

rdis

ed

com

pone

nt w

hich

rea

dily

ava

ilab

le

in th

e m

arke

t, m

ake

ease

for

co

mpo

nent

rep

lace

men

t if

requ

ired

.

Eff

icie

nt h

andl

ing

and

asse

mbl

y op

erat

ion

P

reve

nt r

aw m

ater

ial

dam

age

due

to te

mpo

rary

st

orag

e

R

equi

re s

kill

ed w

orke

r fo

r sp

ecia

lise

d w

orks

.

Process integration

Sho

rter

con

stru

ctio

n ti

mef

ram

e

Pai

d-of

f lo

ng p

roje

ct

plan

ning

D

esig

n w

ork

and

com

pone

nt

prod

ucti

on p

rogr

ess

sim

ulta

neou

sly

Eff

ecti

ve c

oord

inat

ion

betw

een

stak

ehol

der

due

to lo

ng-t

erm

co

mm

itm

ent

R

educ

es u

nnec

essa

ry ti

me

and

effo

rt

wit

h pr

oper

pla

nnin

g at

the

earl

y pr

ojec

t pha

se

Sub

stit

utab

ilit

y of

op

erat

iona

l and

m

aint

enan

ce

arra

ngem

ent

L

ong-

term

sup

ply-

chai

n en

gage

men

t for

rep

lace

men

t co

mpo

nent

sup

ply

or to

sup

port

fu

ture

cha

nges

.

Ava

ilab

ilit

y of

spa

re

part

s fo

r fu

ture

m

aint

enan

ce o

r m

odif

icat

ion

purp

oses

Low

pos

sibi

lity

of

mat

eria

l or

com

pone

nts

outa

ge

A

void

del

ay d

ue to

wea

ther

and

late

de

live

ry.


6.3.1 Environment

IBS offers a significant contribution to environmental sustainability by

providing a sustainable resource supply and stable environmental quality. The Delphi

panellists agreed that IBS application promotes optimisation in material and energy

consumption. This resource efficiency tends to increase by the degree of prefabrication

(El Khouli, John, Zeumer, & Hartmann, 2015). By optimising the amount of resources

and energy required to build physical infrastructures, the loads imposed by the

construction industry on the extraction of the natural environment can be minimised.

Furthermore, the efficient use of energy and resources in product industrialisation and

mass production helps to reduce the impacts of global climate change. This is

achievable by lesser consumption of required energy from fossil fuels (Pearce et al.,

2012), leading to conservation of limited natural resources for future generations.

In addition, sustainable IBS minimises on-site wastage, which is one reason for

why IBS is a preferred solution. Furthermore, industrialisation relocating major

construction activities to the factory will lead to the simplification of on-site

construction activities. On-site works, such as cast in-situ, plastering, and tiling may

no longer be required (Jaillon & Poon, 2008). Waste generation from timber

formwork, leftover concrete mix, and furnished material at the construction site is

usually taken to the dumping area. Appropriate storage and handling of raw material

under a controlled environment to prevent material spoilage or damage would lead to

less waste generation. Elimination of such waste diminishes the misuse of resources

and creation of land pollution issues, therefore sustaining natural assets and

environmental quality of the natural environment.

Yunus (2012) previously suggested that IBS buildings could be relocated or that

the dismantled components could be reused. However, there was lack of agreement

between the Delphi panellists regarding IBS dismantle ability which casts doubt over

whether options for recycling or reuse would contribute to infrastructure sustainability.

The panellists apparently unsure about the practicality of dismantling the IBS

components. This reflects one interviewee’s comment that it is very rare in the local

industry to dismantle a built structure piece by piece with the intention of recycling

and reuse. There is possibly a lack of options and available initiatives in relation to

regenerating the used components into usable or adaptable restored products.

However, this does not mean that IBS would not provide the advantage of a


disassembling ability that provides flexibility for modification and expansion. It is

important for the built infrastructure to have this advantage to deal with evolving user

demands over time (Ye et al., 2009). The consideration for future expansion in the

master plan is influential to ensure that the type of IBS to be used is adaptable for

future changes. The extent of the IBS to support future redevelopment is discussed

further in Section 6.4. To cope with the growing demand, it may be unnecessary to

build a new built facility at a different site that requires new material flows from the

nature extraction. After all, the abandoned infrastructures will terminate the life cycle

of the consumed material as wastage.

6.3.2 Social

From the social dimension of sustainable infrastructure, there are concerns

relating to how individuals, communities, or societies are benefited and affected

(Colantonio, 2011). In this research context, adoption of IBS as the construction

method provides several intangible social benefits throughout the infrastructure project

delivery; the quality of life of the communities and long-term benefits for the workers.

Meanwhile, the characteristics of IBS itself promotes social equity in terms of

architectural elements and accommodating potential redevelopment.

The implementation of IBS as a simple construction process was highly rated as

a sustainable attribute. Presumably, IBS adoption that involves assembly-type

operations minimises significant risk factors. Although this may be true, some of the

Delphi panellists did not agree that “minimal on-site risks” was a sustainability

attribute of IBS application. This may be reasonable, as even though on-site fabrication

is absent, other potential risks during handling and assembling components could

occur. However, as labour-intensive works have been taken over by the

manufacturing-oriented working system, human fatigue-related risk could be reduced.

Previous studies have shown that workers tend to make errors, therefore potentially

causing an accident in a fatigued state (Fang, Jiang, Zhang, & Wang, 2015). In the

factory control setting, workers are usually assigned to a designated work station

equipped with appropriate safety protection and they usually are protected from

inclement weather and temperature extremes. All of these issues emphasise that IBS

could potentially eliminate the public perception of the construction industry as being

“dangerous, dirty, and difficult”.


It is important to note that IBS requires skill and competency for successful

implementation. IBS implementation demands a higher level of skills, not just for the

contractor, but throughout the entire supply chain (Abd Hamid et al., 2017).

Correspondingly, increasing job skills should improve the image of the construction

industry, therefore creating awareness and attractiveness among the local workforce

to join the industry (MIDF, 2014). As a result, this could reduce the dependency of the

construction industry on unskilled foreign labour, as well as the attendant social

problems and money outflow overseas.

Various perceptions and opinions were raised when considering IBS

applications in infrastructure projects. Some infrastructure, such as airports, towers,

mosques, and bridges are purposely built as iconic national landmarks and provide

prestige value. They are built in an innovative and sophisticated architecture design.

Several interviewees in this study believed that it is challenging for IBS to cope with

the aesthetical features of built infrastructure. This is consistent with Tam, Tam, Zeng,

et al. (2007) who claimed that IBS buildings commonly feature monotony in their

architectural design. Even so, this study acknowledges that IBS provides the option

for customisation through product industrialisation. The point that is often overlooked

is that IBS has several types of application where the capacity and characteristics of

each are not necessarily similar. It is crucial to choose the appropriate IBS system in

accordance to the type of components to suit particular design requirements.

Furthermore, emerging manufacturing and production technologies make

customisation in component design practical and workable. Through the revolutionary

technology of computational design and advanced manufacturing techniques,

architecture enjoys freedom for the delimitation of design, production, and

performance of novel architectural forms, construction systems, and the material

employed (Paoletti, 2017). This correspondingly demonstrates that IBS application

does not have to be bland, and that the strength of the various alternatives will deliver

stylish look of the built infrastructure.

On the other hand, built infrastructures are expected to provide long-lasting

service to society. Over the years, built infrastructure ages and may require upgrades

to meet capacity requirements, as well as improving its appearance to provide comfort

and a pleasant look. Rapid population growth and city expansions create pressure on

urban development authorities to extend infrastructure and services to cope with


increasing demand (Teriman et al., 2010). Sainz (2012) also claimed that it is essential

for infrastructure to be attractive to satisfy the needs of consumers. Therefore, as a pre-

requisite, infrastructure development needs to consider appropriate design and

construction systems that are capable of supporting such requirements. The ability of

IBS to support future redevelopment through its flexibility and modification capability

ensures that the provision of services rises in parallel with growing demand. It

promotes sustainable infrastructures, thus warranting the sustenance of service

provision for the long-term. The consideration of consequences of prior decisions for

forthcoming events is a foundation for sustainable development (United Nations

ESCAP, 2006).

6.3.3 Economic

The contribution of IBS to the economic pillar is attributed to the direct costs

and indirect costs. Upfront investment and life-cycle costs are the generic cost

distribution for the direct costs (Ugwu & Haupt, 2007). Behind these are many other

cost variables that influence the economic performance of IBS application, which also

includes changes in indirect costs due to the corresponding performances, such as

quality, productivity, health and safety, environmental, and adaptability.

Based on the discussion about IBS drivers and challenges in Sections 6.2.3 and

6.2.4, there were positive and negative economic implications regarding IBS

application. Optimisation of resources could perhaps be the major factor relating to

cost savings. Less material and auxiliary equipment, less wastage, and less labour may

lower project costs. On the other hand, indirect savings are secured from avoidable

disputes such as fewer errors, less pollution, and less potential safety risks due to better

quality control, minimal environmental impact, and convenient and safer workplaces.

However, savings in such costs do not necessarily lead to minimisation of construction

costs. Cost savings obtained in the construction activities are actually replaced by

advanced investment on the facilities of component production. Major construction

costs are required for the component production and delivery of IBS components. This

is a benefit for mega-scale projects where economy of scales can be achieved with

high-volume component productions. However, IBS does not necessarily eliminate

certain costs. For example, even though the cost of transporting material is reduced,

the cost of component delivery is then required. This may require an excessive cost for

oversize and sensitive structures. Hamzeh et al. (2017) also claimed that transporting


precast elements through narrow and steep roads, especially during the rainy season

may provide logistical challenges. This may have been why the stakeholders believed

that cost savings relating to the transportation of material are not necessarily relevant

to contributing towards sustainability.

Ultimately, the potential of IBS for optimising the life cycle cost of infrastructure

is undeniable. Over the infrastructure life-cycle, operational and maintenance costs

dominate the life cycle costing until the end of the life of the assets. It is significant

that the use of quality components may lead to a longer lifespan for the infrastructure.

Infrastructure is required to be able to provide service over a prolonged period, which

requires regular maintenance and possible modification to upgrade capacity. The

flexibility of the IBS to be adaptable to change prolongs the service lifetime of the

built assets, rather than building new infrastructure to cope the growing demand, which

is not an economical solution.

As can be seen, improvement to environmental and social pillars contributes to

better economic value. This demonstrates the interdependencies among the

sustainability pillars. Collaborative decision making between the project stakeholders

during early project planning and design offers excellent opportunities to optimise the

project’s resources, including manpower, money, and materials over the built

infrastructure’s life cycle.

6.4 PROMOTING IBS APPLICATION IN INFRASTRUCTURE PROJECTS BY CONSIDERING FUTURE REDEVELOPMENT

In addition, to enhance the sustainability of built infrastructure, redevelopment

potential was also examined in this study. The need for redevelopment of infrastructure

depends on the lifetime of the built infrastructure and its existing performance. After

a certain period, infrastructure may require redevelopment to cope with growing

demand, enhance the physical appearance, or upgrade aging facilities. This aligns with

Gerencser and Hamilton (2011) who highlighted that infrastructures are in desperate

need of recapitalisation and modernisation after very long service to accommodate

new technology and growing population necessities. This section therefore discusses

the extent to which IBS could provide flexible construction systems to facilitate

infrastructure redevelopment.


Adaptability can be seen as a sustainability practice by exercising reduction,

reuse, and recycling in the built environment (R. I. Schmidt & Austin, 2016). It could

very well provide an alternative to new construction, to “reduce” the requisition of

resources extraction. In addition, adaptability puts forward the “reuse” concept of re-

life for abandoned or underutilised building stock and promotes the “recycle” ability

by enhancing disassembly or deconstruction of components to prolong the useful life

of existing infrastructures. The findings from the Delphi study indicated that IBS offers

adaptability through several criteria, namely that it is versatile, adjustable, refitable,

scalable, moveable, and convertible. These adaptability criteria depend on the

dichotomy of the built infrastructure, motives of adapting, and type of required

changes (R. I. Schmidt & Austin, 2016).

Correspondingly, from this study, IBS was believed to be flexible in relation to

future changes. Redevelopment potential may involve changes in many spectrums,

including changes of location, function, space, size, and performance. This reflects

Sadafi et al. (2012) in that the indicated function requirement, disappointed

performance, aesthetic and organisational shift, property market value, and adaptation

of new technology, standards, and codes lead to the respective changes. How the

changeability and adaptability criteria of IBS facilitates infrastructure redevelopment

will be further discussed.

Infrastructures may become physically or functionally obsolete for various

reasons (Swallow, 1997). Infrastructures start aging as soon as the construction phase

is completed. Over years of service, the performance of infrastructure may fall below

the required standard or no longer correspond with leading technology, leading to the

need to upgrade or at least maintain the health of the infrastructure.

In considering the potential of infrastructure changing its function or modifying

its layout, the discussion may be more relevant for abandoned or unattended building-

type infrastructures. Conservation of such buildings will prolong the service value,

therefore encouraging an efficient use of resources by facilitating environment

sustainability, and promoting social and cultural worth (Y.-H. Hsu & Juan, 2016;

Myers & Wyatt, 2004). It should also be noted that the design of built infrastructure

represents the image of its function. Infrastructure is primarily designed according to

a specific function. According to Schmidt and Austin (2016), the capacity for

conversion of space to accommodate a new function depends on the capacity and


location of various physical elements. For this reason, the more similar the structural

typologies, the easier conversion would be. It therefore seems that the criteria of

sustainable IBS are that it employs the standardisation of components to support this

requirement.

On the other hand, refurbishments aim to upgrade tired facilities with a means

to reducing obsolescence while enhancing performance and occupant satisfaction (S.

Shah, 2012c). This is an innovative and sustainable method of preserving embodied

energy in the existing building stock by reusing it instead of demolishing it. The

reclamation of components and the carbon embedded in them sustains resource

conservation (Iacovidou & Purnell, 2016). Moreover, a new build requires massive

construction material, while most cases of refurbishment projects may feasibly include

the reuse and recycling of existing building materials (S. Shah, 2012a). The less waste

generated, the more embodied energy of the construction material is conserved

(Lawson et al., 2012). A benefit of IBS is that it enables easy “assembly and

disassembly” and ensures the physical and technical properties of the recovered

components are suitable to be reused. Precision-machined parts also imply good

quality and durable components, which are therefore more resistant to disintegration

(R. I. Schmidt & Austin, 2016). Kincaid (2002) found that steel frames are the

preferred type of structure for “change of use”. Furthermore, the employment of

standard sizes and connections in IBS applications creates greater opportunities for the

components to be fitted in other applications. To enable efficient reusability and

recyclability of the structural components, it is essential to consider the properties of

components, the nature of the recovery process, and the nature of the original use

(Iacovidou & Purnell, 2016).

For better utilisation of buildings, flexible use of space that promotes

multipurpose would provide a social benefit. S. Shah (2012) indicated that commercial

buildings should be flexible and complex to allow layout modification and promote

multi-functionality for a potential change of use in the future. The versatility of IBS to

accommodate this is through the provision of open space, for example, by using steel

structures. Steel could provide a very long spanned structure without intermediate

columns. R. Schmidt and Austin (2016) claimed that the movability of prefabricated

walls, furniture, and fixtures would facilitate the reformation of a floor plan. Adopting

modular components or a modular unit for amenities such as elevator systems,


staircases, and toilets also increases the adjustability of the space arrangement.

Furthermore, modular systems allow for easy-separation of constituting parts with

minimal damage (R. I. Schmidt & Austin, 2016). However, the availability of this

function depends on how the modular units are mounted to each other. This requires

careful consideration in the design phase to establish the reversible capacity of the

particular IBS type used.

It is important to note that the health of the structural element will depreciate

over decades of service for many reasons, such as deterioration due to internal or

external damage. If this continues, it will disrupt the performance of the infrastructure,

and the service needs may be stopped. For infrastructures that use steel or timber

structures (e.g., bridges, rail tracks, roof trusses, etc.), as well as prefabricated parts or

modular systems, replacement of deteriorated or broken components can be as easy as

“plug and play”, as long as this does not interrupt the adjacent elements. The

replacement parts can be fabricated off-site, meaning the recovery process will be

shorter. In order to allow easy replacement, it is of upmost importance to design the

infrastructure with the ability to disentangle. Otherwise, the advantages of IBS cannot

be fully optimised.

In addition to regular maintenance and repair works that focus more on short-

term solutions, built infrastructures should be shifted to a universal response through

retrofitting practice (May, Hodson, Marvin, & Perry, 2013). This is especially essential

for older built assets to improve their energy performance to comply with the current

regulations or certification requirements (Appleby, 2013). For example, this may

involve façade renovation or replacement, or new installation of cladding, glazing, or

fenestration. Utilisation of prefabricated components for these elements, especially

standard or market-ready products, increases future accessibility and replaceability,

allowing for renovation works to be undertaken over a short period. Meanwhile, major

renovation works that takes longer require an efficient and simplified process to limit

disturbance to the occupants. R. Schmidt and Austin (2016) claimed that the utilisation

of standardised elements with standardised installation routines would expedite this

process. Malacarne et al. (2016) and Bystedt et al. (2016) also agreed that

refurbishment time and resource savings could be achieved by adopting IBS systems.

In the meantime, the refurbishment of the external fabric will provide a face-lift for

the exterior architecture In essence, the physical characteristics and features of an


infrastructure can influence the market value of the property (Kincaid, 2002).

Renovation of infrastructure that once blighted the community may now present an

iconic image of construction and architectural innovation (Elrod & Fortenberry, 2017).

In the event that the refurbishment and layout modification is no longer able to

cope with growing needs, more extensive infrastructure redevelopment, such as

extension or expansion of the existing infrastructure could be a better solution. Using

urban infrastructure as an example, changing demands for transport facilities are

rapidly emerging (Kincaid, 2002). Rapid urban growth requires expandable facilities.

The existing infrastructures need a continuous recovery process or incremental

expansion from time to time to counterbalance the demand and support sustainable

urban growth (Cho, 2011). For congestible infrastructures, such as rail transport

facilities, airports, and seaports, the expected demand is projected in the project

planning phase. Usually, the original design has considered this possibility and

provides allocation for future expansion or extension. For these types of built

infrastructures, renovation works should not interrupt the current service provision. In

cases where this infrastructure is located in an urban area, with limited space for

construction works and potential disturbances to traffic flow, an appropriate IBS

system may facilitate and speed up the upgrade process. By utilising pre-manufactured

components or modular systems, very minimal activities are conducted on-site,

allowing the upgrading process to be completed faster. For an expansion or extension

project that requires partial deconstruction, there is an advantage if the original

structure was designed using an IBS system that allows for the detachment of

components or elements. Such a design ensures that structural elements or components

would easily and expeditiously adapt to the new design (Sadafi et al., 2012).

Implementing an innovative design with a simple erection, using market-ready

components, and practicing extensive lean management procedures could improve the

efficiency of IBS implementation and is the way forward in modern construction.

Even though it is unlikely that mega-infrastructures, such as bridges, airports,

and transit hubs have the potential to be relocated, built facilities such as construction

worker accommodation, temporary bridges, and toll booths may be able to be reused.

Other examples are buildings that lend to transient events, such as temporary pop-up

stores, theatre sets, etc. These types of building typologies can be equipped with

disassembly ability or built in a modular style to allow easy removal and reset-up (R.


I. Schmidt & Austin, 2016). The portable nature of these built units could promote

reusable practices while optimising the utilisation of resources, especially construction

materials. However, the durability of the connection system should be considered in

relation to repeated cycles of re-assembling.

6.5 IBS STRATEGIES FOR FACILITATING FUTURE REDEVELOPMENT OF BUILT INFRASTRUCTURE

Regardless of the various mechanisms for potential redevelopment, the existing

built infrastructure currently using IBS does not necessarily support future

redevelopment satisfactorily. The characteristics of IBS could provide a significant

contribution to this need (as discussed in Section 6.4) only if the implementation is

carried out properly. Otherwise, the benefits of IBS would not be optimised. According

to the Delphi study, the panellists disagreed that the flexibility and dismantle ability

offered by IBS were the drivers for its implementation. However, the panellists also

disagreed with lack of flexibility being a challenge for IBS application. This shows

that the panellists did not reject the flexibility of IBS entirely. This may be reasonable

because the flexibility of IBS may only apply when there is an initial intention and

extensive consideration during project planning. In order to support the ability of IBS

in facilitating future redevelopment, several important aspects require further attention

and effective strategies. According to the Delphi results, 21 strategies were considered

relevant, as they reached satisfactory agreement among the panels. The strategies were

proposed based on the findings from the literature, interviews, and the Delphi study.

To ensure the target is achievable, it must be included while developing the

strategic plan. It is therefore important for the project initiator to consider the potential

for future redevelopment at the beginning of the project phase. This is consistent with

Morrissey et al. (2012) who incorporated development of adaptation strategies into the

infrastructure project appraisal. Every sub-sequential decision will then be based on

and led by this condition. While redevelopment potential is brought forward from the

post occupancy phase, it was believed that adopting a long-term procurement system

would also be beneficial. Over the years of service, innovations in infrastructure

operation and maintenance may call for re-organisation of contractual obligations and

financial recourse (Tawiah & Russell, 2008). Correspondingly, procurement

arrangements must incorporate open-ended terms, encourage sustainable construction,

and facilitate optimisation of the infrastructure lifecycle. Similarly, the designer is


responsible for ensuring that the infrastructure design is innovative enough to cope

with future demand. It is worthwhile to foresee potential changes to allow for

adaptation consideration in the design process. However, all stakeholders must

understand and establish mutual sustainability objectives. This requires the

involvement of all stakeholders including the contractor and suppliers or product

manufacturers at the beginning of the project, to ensure all information is properly

transferred. Every stakeholder has different skills, knowledge, and experience. Sharing

mutual goals, strategies, and action plans will enhance mutual dependence. This may

promote higher potential for cooperation, where by supporting other parties, both

parties will enjoy their respective benefits (Bosse & Coughlan, 2016). The above

actions are essential elements in the planning phase and design decisions for

infrastructure project delivery.

Corresponding to the generic design requirements, the selection of the relevant

IBS type is a vital aspect to enhance the adaptability of built infrastructure. Reducing

the complexity of structural systems allows for the components to be dismantled

easily. This strategy contributing to the deconstructability of the assembled

components (Sadafi et al., 2012). Another important strategy to make this possible is

by avoiding wet-trade connections between panels. An in-situ concrete connection

would limit the opportunities for dismantling (Jaillon & Poon, 2014). Employing dry-

joint connecters (Chica et al., 2011; Liu et al., 2015) and removable fasteners (Kubba,

2017) is more feasible for disassembly. Using modular wall panel systems or structural

components for interior walls and disentangle utility systems would allow for easier

modification of space. Such designs would be in compliance with IFD (industrialised,

flexible, and demountable) building technology (Richard, 2006) and the DfD

(designed for disassembly) concept introduced by Crowther (2005) that increase the

flexibility of elements and parts to be relocated or reused in a simple and expeditious

manner. Furthermore, to simplify the demounting of the existing built components and

to install the components for an additional or new structure, a standard, low-tech and

simple construction technique is significantly favourable. In the event that the

redevelopment project progresses while the infrastructure is under service, it must be

done effectively and quickly. This could consequently reduce interruption and

downtime for the occupants during the renovation works (Sadafi et al., 2012).

Regardless of which type of IBS approach is adopted, it is crucial for the designer to


understand the capacity and limitation of the different kinds of IBS in adapting to

changes. A collaborative engagement between the designer and the component

suppliers or product manufacturers could provide innovative IBS solutions in

facilitating future redevelopment of built infrastructure.

Among the agreed strategies, there are four concerns about the component

design and material selection. Adopting lightweight material makes the redevelopment

works progress quicker in addition to creating easier component handling. Using the

standard components and standard connections with a limited variant of specification

could improve the practicability and efficiency of IBS. If the replacement of damaged

components is required, the components could be supplied instantly. The dismantled

elements (components or connections) could then possibly be reused for another

purpose, for example, reused in another redevelopment project or another new

construction project. In addition, considering highly reusable material could support

the reusability of the IBS component. With this intention, consideration of disassembly

design should be included in the design strategy to ensure that the material can be

reused effectively (Kubba, 2017). Accordingly, Sadafi et al. (2012) also emphasised

that the compatibility of connections between components could facilitate space

modification. Thus, innovation of connections systems for easy erection and

dismantling, such as the “plug and play” concept, would improve IBS efficiency.

These practices demonstrate remarkable strategies for material and component

recovery solution.

It is also important to note that redevelopment of infrastructure is commonly

required after decades of operation. Over this period, the stakeholders’ representative

may change. Partnership or engagement between the project team provides long-term

business relations, therefore extending the cooperation opportunities beyond single

projects (Andersson & Lessing, 2017). For example, whenever component

replacement is required, the supplier could instantly provide the spare-parts and for an

extension project, they could provide technical and product consultation for design

adaptability. However, well-documented project documentation makes it possible to

hire an external consultant team for continuation works (Andersson & Lessing, 2017).

All information regarding the building construction system that provides design,

logistics, assembly, and disassembly procedures should be kept and maintained

properly. Otherwise, inadequate knowledge will mislead the maintenance contractor


while recognising any defects during inspection and planning works (Z. A. Ismail,

Mutalib, & Hamzah, 2016). Such relevant technical information is an important

reference for the decision makers to plan and execute redevelopment projects. It also

becomes a compulsory reference for the designer to design a compatible new structure

to be adapted to the existing structure. It clarifies the limitation of the building system,

such as in terms of geometrical dimension, loading, bearing capacity, and so on

(Andersson & Lessing, 2017), while providing permanent identification marking on

the components and connections used could enhance IBS adoption. This strategy

allows for the target elements to be easily recognised. The availability of this

information would avoid confusion, make the rectification process faster, and

redevelopment works could then be undertaken in a coordinated way. Altogether,

long-term relations between project players, in addition to thorough construction

documentation and identification of components, will support IBS accessibility for

facilitating redevelopment projects.

The key strategies of adopting IBS to facilitate future redevelopment have been

addressed. Redevelopment of an infrastructure would not only be easier and cheaper

using IBS application, but would also move towards a closed loop of material lifecycle

while minimising environmental impacts. Regardless of the abovementioned strategies

with specific objectives, extensive knowledge and comprehensive experience are

required to guarantee the effectiveness and efficiency of IBS application. IBS could

provide an adaptability advantage if redevelopment potential was considered

beforehand. Perhaps in the future, adaptability will no longer be the exception, instead

becoming a compulsory requirement in infrastructure project planning.

6.6 DEVELOPED SUSTAINABLE IBS APPLICATION FRAMEWORK FOR INFRASTRUCTURE PROJECT

The final objective of this study was to develop a framework for delivering

sustainable IBS in infrastructure projects. The framework aims to improve IBS

deliverable practices by incorporating the consideration for future redevelopment in

infrastructure projects, as illustrated in Figure 6-4.

Firstly, this framework provides four important consideration factors while

contemplating IBS adoption in infrastructure projects. In order to implement effective

decision making in infrastructure project planning these factors should be taken into

consideration to ascertain that the efficiency of the IBS application i achievable.


Realistically, there are various limitations and challenges (see Section 6.2.4) to

ensuring that the implementation of IBS in project infrastructure delivers in sustainable

ways. However, IBS has also been recognised for its contributions and benefits (see

Section 6.2.3) that promote sustainable construction practice. These limitations and

benefits are dynamic in the sense of which approach is used or how the implementation

is executed. By reviewing both, practical solutions for delivering sustainable IBS in

infrastructure projects can be derived. Therefore, based on the key factors identified,

the framework is expected to provide stakeholders with primary guidance for adopting

IBS innovations.

Secondly, moving towards sustainable development, there is a call for the

construction industry to extensively embrace the concept and importance of

sustainability in project delivery, with no exception for infrastructure development.

The Construction Industry Transformation Plan (CITP 2016-2020) initiated by the

Malaysian government targets raising Malaysia’s infrastructure as a model for the

emerging world (CIDB, 2015). This thrust urges the industry to respond by delivering

more resilient and sustainable infrastructure. This framework also presents the

elements of sustainability performance for infrastructure projects through IBS

application, which should allow stakeholders to create a vision and shift the

construction industry towards more sustainable construction practices.

Finally, to extend the potential of sustainable IBS, this framework incorporates

the potential of built infrastructure redevelopment in the future. The framework

outlines the expected adaptation works to cope with changing demand. This should

help stakeholders to determine the anticipated necessities that have to be considered

during project planning and design decisions. In order to manoeuvre the capability of

IBS to facilitate redevelopment activities, the delivery of the IBS application must

emphasise the practical strategies in planning and design, IBS system selection,

component and material selection, as well as accessibility provision. Expanding on the

graphical presentation, the IBS strategies and intended outcomes are demonstrated in

Figure 6-5.


F

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6.7 SUMMARY

This chapter discussed the research objectives through the synthesised results

and findings from the semi-structured interviews and the two-round Delphi study. The

discussion was also supported by the relevant literature. Firstly, the construction

practitioners’ understanding and perceptions of the IBS application in infrastructure

projects was discussed, including the concept, drivers, and challenges of IBS

implementation. The consideration factors of IBS implementation, particularly in

infrastructure projects, comprising of design requirements, project characteristics,

policy, and industrial readiness were also addressed thoroughly in the same section.

The following sections discussed the contribution of IBS in delivering sustainable

infrastructure. The discussion was sub-divided according to the three pillars of

sustainability: “environment”, “social”, and “economic”. Sustainability can only be

achieved through the holistic harmoniousness of all pillars. Accordingly, the

significance of redevelopment in promoting the sustainability of built infrastructure

sustainability was also explained. IBS application strategies for facilitating future

redevelopment were then consolidated based on the Delphi study. The strategies

constituted from the planning and design rules, IBS system selection, component and

material selection, and accessibility. All of the findings were derived and lead to the

establishment of the “Framework for delivering sustainable IBS in infrastructure

projects”. Finally, the contribution and the prospect of the framework concluded this

chapter.

Chapter 7: Conclusion 227

Chapter 7: Conclusion

7.1 INTRODUCTION

This thesis is comprised of seven chapters. Chapter 1: presented the research

background, in addition to the research objectives derived from the identified research

questions. Chapter 2: discussed the current state of knowledge and previous research

works relevant to the research topic through an extensive literature review. Chapter 3:

described the research methodology corresponding to the research questions. Chapter

4: and Chapter 5: reported the results and outcomes of data collected using semi-

structured interviews and a Delphi study, respectively. Chapter 6: synthesised all of

the findings and discussed the perception of IBS application in infrastructure projects,

IBS sustainability, redevelopment of built infrastructure, and finally, presented the

developed framework of sustainable IBS application in facilitating redevelopment for


This chapter presents a summary of the findings by reviewing the research

questions and drawing a conclusion, respectively. It also provides the research

contributions, limitations, and future research opportunities.

7.2 REVIEW OF RESEARCH OBJECTIVES AND DEVELOPMENT PROCESSES

The objectives of the research were established based on the recognised research

gaps from the systematic literature review, as thoroughly discussed in Chapter 2:. This

research sought to achieve the following objectives:

RO1: Explore the current status of IBS application in infrastructure

development.

RO2: Identify IBS application contribution to infrastructure sustainability.

RO3: Examine the potential of IBS in facilitating the redevelopment of built

infrastructures.

228 Chapter 7: Conclusion

RO4: Develop a framework of sustainable IBS application for infrastructure

projects.

The research objectives provided a clear direction as a strong foundation to

achieve the research aim. This research used a multi-approach for data collection and

data analysis. Semi-structured interviews were carried out with 20 industrial

practitioners and researchers who were experienced in IBS application. Interviews

were used to capture the perception of the industry in relation to IBS application in

infrastructure projects, the significant factors for choosing IBS, and contribution of

IBS application in promoting sustainability. This feedback helped achieve the first and

second research objectives. Accordingly, a two-round Delphi study involving 15

experienced professionals and academics was then conducted. The literature and

interview findings were used as the foundation for the Delphi questionnaires. The

Delphi study also refined the preliminary findings from the interviews to reinforce the

relevant findings for the third research objective based on the panellists’ consensus.

Triangulation of the results and outcomes then led to the formulation of a framework

for sustainable IBS application for infrastructure projects that achieved the fourth

research objective.

7.3 KEY FINDINGS

The well-established research objectives led this research to achieve the research

aim. Five research questions were developed to address those objectives. The key

findings from the interpretation of the research analysis are described and presented

according to the research questions in the below subsections.

7.3.1 Extant Literature

The literature on IBS application that supports the sustainability of construction

projects has progressively increased in recent decades, as reviewed in Section 2.4.4. A

comprehensive literature review was undertaken regarding the existence of previous

research about IBS application in infrastructure projects, in addition to its contribution

to sustainable development. The literature review provided an overview of the existing

research and gathered information relating to IBS drivers and limitations, innovations,

delivery strategies, and sustainability related issues. Even though research about IBS

application in regard to sustainability concerns has gained significant attention in

recent years, this review provides an interesting addition to the field of IBS


implementation within an infrastructure projects context. Understanding the state-of-

the-art research trend that integrates IBS, infrastructure, and sustainability suggests a

road map for researchers in exploring the gaps in the body of research within these

areas. The adaptability and practicality of IBS application in infrastructure projects are

important topics in need of clarification. In addition, there are gaps to be explored in

relation to research about the sustainable potential of IBS in the post construction

phase, as most previous studies have focussed solely on the pre-construction and

construction phases. To enhance IBS application in infrastructure projects,

construction practitioners require decision support guidelines to assist them to deliver

more sustainable infrastructure. Accordingly, this led the researcher to conduct this

research to develop a framework of sustainable IBS application in facilitating

redevelopment for infrastructure projects.

7.3.2 Research Question 1

RQ1. What are the perceptions of the construction industry with regard to IBS

application in infrastructure projects?

The literature review determined that there is limited research that emphasises

infrastructure projects while researching IBS sustainability. The interpretation of IBS

is often associated with multi-storey building projects. This may be reasonable,

because the introduction of IBS by the CIDB was initially undertaken to encourage a

low-cost housing scheme in Malaysia (Hamid et al., 2011). However, IBS is

supposedly not limited to a specific type of project. The construction practitioners

show their mutual understanding that this kind of construction system involves

production, delivery, and installation process.

The interviews indicated that the construction industry has paid attention to IBS

application and made a relatively good impression in regard to the ability of IBS as a

modern construction method. Regardless of the many general IBS benefits and

limitations found in the literature, this research discovered that there are multi-

perspectives of IBS drivers and challenges for infrastructure projects. IBS application

in infrastructure projects was believed to be driven by the 25 factors categorised into

seven main clusters: (1) productivity, (2) quality, (3) environment, (4) safety and

health, (5) constructability and design, (6) cost, and (7) policy and regulation, with the

results indicating that “productivity” is the most dominant. Each of the clusters was

comprehensively discussed in Section 6.2.3. In addition, this research also recognised


that IBS application may be jeopardised by 16 potential challenges due to discrepancy

in project planning, cost-related issues, site constraints, and immature industry

capacity, as explained in Section 6.2.4. Cost-related factors were found to be the most

prevalent. However, every driver or challenge is not necessarily relevant to all

stakeholders, which each stakeholder should be aware of in the pursuit of addressing

the needs and satisfaction of other stakeholders in their decision making. This led to

the identification of the best practices for IBS delivery, which require holistic

judgement between embracing the benefits and encountering the challenges among

stakeholders.


RQ2. What are the important elements or factors for infrastructure projects to apply

or adopt IBS?

This research formally identified four categories of important elements that

should be considered when implementing IBS in infrastructure projects. These

elements were initially compiled from the literature reviews and interviews, and then

achieved consensus through the Delphi study among the industrial experts. The

interviews and Delphi study involved representatives from various groups of

stakeholders, such as clients, contractors, consultants, manufacturers, and researchers.

Thus, the findings incorporate a holistic view of infrastructure project execution.

The identification of consideration factors was undertaken to ensure that the

primary decision leads to the expectation of efficient use of IBS. They were grouped

into design requirements, policy, project characteristics, and industrial readiness, as

presented in Table 7-1. IBS is subject to several types of systems and materials.

Practically, a particular system does not necessarily fit into a diversified application.

The specification of designed components, the level of standardisation, and

repetitiveness of employment will affect the efficiency of its implementation. Due to

the complexity of infrastructure projects, the type, size, location, cost, and lifespan of

projects influences the capacity of IBS application. Each infrastructure project may

experience unique challenges depending on the characteristics, in addition to the

different approach of the procurement system. Despite this, whenever the policy of

IBS application has been designated as a project requirement, it becomes a priority to

be implemented. Corresponding to this, the availability of resources, technology, and

expertise are essential for the effectiveness of IBS implementation. This prerequisite


indicates the readiness of the construction industry to shift towards IBS

implementation.

Table 7-1: Consideration factors for IBS application

These findings were included in the developed framework as a foundation for

decision making to optimise the benefits and/or expel the barriers of implementing IBS

in order to ensure that the identified barriers do not become a permanent obstacle and

to ensure the benefits can be projected more efficiently.


RQ3. How can IBS application contribute to infrastructure sustainability?

IBS has received considerable recognition in regard to its contribution towards

sustainable construction practices. This study investigated how IBS application

influences and contributes to the sustainability of infrastructure projects. The results

of the interviews showed that the sustainability of IBS application was interpreted by

the implication of its employment. There are six performance criteria relating to IBS

application that provide sustainability potential in infrastructure project delivery,

including: (1) cost effectiveness, (2) productivity, (3) quality, (4) health and safety, (5)

waste minimisation, and (6) adaptability. Meanwhile, by recognising the IBS

characteristics of product industrialisation, mass-production, transport, and assembly

techniques, structured planning and standardisation, as well as process integration, the

Delphi study determined 19 attributes that contribute to infrastructure project

sustainability.

Responding to the third research question, to ensure that IBS is able to contribute

to infrastructure sustainability, project stakeholders need to optimise the capability of

IBS sustainable attributes in infrastructure development planning. The integration of

• Type of IBS • Specification of

design components • Standardisation of

components • Repetitiveness of

components

• Project size • Type of infrastructure • Type of procurement • Location of project • Cost of project • Lifespan of project

• Availability of resources and technology

• Availability of competent key players ◦ Consultant ◦ Contractor ◦ Product

manufacturer


Design Requirement

Industrial Readiness Policy

• Requirement of project developer

• Requirement of government policy


sustainable performance and sustainable attributes of IBS application towards

infrastructure sustainability are presented in Figure 7-1. Section 6.3 discussed the

synthesis and logics of the interrelation behind each pillar of sustainability. It is

deniable that sustainable contributions cannot be treated in isolation, since in one way

or another, they are interdependent. Understanding and acknowledge this paves the

way to pursue sustainability goals throughout the project life cycle.

Figure 7-1: Sustainable IBS towards infrastructure sustainability


RQ4. How can redevelopment potential promote IBS application in infrastructure

projects?

The main focus of this research was to promote the application of IBS. The need

for built infrastructure to provide long-term services was emphasised in the literature.

This research also suggests that IBS could provide changeability and adaptability

I

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• Minimal nuisance to public • Cleaner construction site • Minimal on-site wastage and

environmental pollution • Better quality control • Precision in component size and

dimension • Option for customisation


• Optimisation in material and energy consumption

• Cost savings by providing economic of scale

Mass-production

• Simplified construction site • Less carbon emission by reducing of

material delivery trips • Flexibility to accommodate

modification and expansion

Transport and assembly technique

• Minimal errors and mistakes due to component aggregation

• Reduced design complexity • Efficient handling and assembly

operation

Structured planning and

standardisation

• Shorter construction timeframe • Effective coordination between

stakeholder due to long-term commitment

• Substitutability of operational and maintenance arrangement

• Availability of spare parts for future maintenance or modification purposes

• Low possibility of material or components outage

Process integration

Cost Effectiveness

Productivity

Quality

Health and safety

Waste minimisation

Adaptability

IB

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US

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E

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US

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capacity to facilitate redevelopment activities, as discussed in Section 6.4. This will

indirectly encourage the application of IBS in infrastructure projects. In order to

simplify the process of redevelopment, IBS should be designed to be adjustable,

versatile, refitable, convertible, scalable, and movable to accommodate changes of

space, performance, function, size, and location. Therefore, to optimise IBS for

redevelopment purposes, the incorporation of potential redevelopment into project

planning and design will assist stakeholders in establishing a synchronised

consideration in their decision making. Technically, this requires mindful decisions in

selecting the right type of IBS, in addition to component and/or material selection.

Moreover, the implemented system should provide access to allow for and

accommodate future redevelopment works.

The final outcome of this research is a framework for sustainable IBS application

in facilitating redevelopment for infrastructure projects (see Figure 6-4). The

framework encapsulates the sustainability of IBS application through multiple

decisions relating to consideration elements, such as design requirements, policy,

project characteristics, and industrial readiness, in addition to promising sustainability

achievement with the inclusion of redevelopment potential. A list of proposed practical

strategies for implementing IBS to facilitate changeability and adaptability, as well as

the intended outcome also are presented in Figure 6-5. The formulated framework

and guidelines that provide adequate information from holistic perspectives can be

used by the industry to achieve optimal decision making for IBS application in


7.4 RESEARCH CONTRIBUTIONS

The contributions of this research to academic knowledge and industrial

practices are presented in the following subsections.

7.4.1 Contributions to Academic Knowledge

The findings of this research make a number of contributions to the body of

academic knowledge. Research on IBS has increased in recent years; however, studies

relating to its implementation in infrastructure projects are scarce. This research

enriches IBS literature by examining the industrial perception of IBS application in

infrastructure projects. The identification of consideration factors for implementing

IBS is a significant contribution to acknowledge the applicability of IBS in multi-


faceted infrastructure projects. In addition, by scrutinising the drivers and barriers of

IBS application, the present research has revealed the capability and capacity of IBS

for promoting sustainable infrastructure development; thus, providing a broader range

of coverage for IBS research regarding its implementation and its contribution towards

sustainable development.

This research enriches the literature by presenting the potential of IBS in coping

with future demands. IBS has been identified as an option to promote flexibility and

interchangeability. This research explains the capability of IBS to manage types of

changes and adaptation. It also reveals that planning and design, IBS system selection,

component and material selection, as well as accessibility are important to ensuring

the adaptability and changeability of built infrastructure.

The sustainability of an infrastructure project development has attracted many

researchers who have studied various delivery approaches across the project life cycle.

This research provides the inclusion of the post-construction phase into consideration,

highlighting the redevelopment potential of built infrastructure. By optimising the

changeability and adaptability principles of IBS, this research has revealed a list of

ideal practical strategies to enhance the effectiveness of IBS application to facilitate

future redevelopment.

This research derived the theoretical contribution through a systematic literature

review, findings from the interviews, and a Delphi study. This combination represents

a new framework that provides a better insight into the IBS application for

infrastructure projects, with the inclusion of redevelopment potential of built

infrastructure. In this regard, the framework fills a significant gap in the literature,

suggesting consideration of potential redevelopment at the project level in

infrastructure development. Conceptually, it also advances the theory and application

of IBS as a tool for supporting infrastructure sustainability.

From an academic perspective, it broadens and deepens the construction

engineering, and management research across the entire facility lifecycle and fuels

demand for construction approaches that incorporate sustainability issues in the early

phases of infrastructure development, as recommended by Levitt (2007).


7.4.2 Contributions to the Industry

This research has discussed a unified definition of the concept and the

interpretation of IBS application in the Malaysian construction industry. The study

addressed the consideration factors, benefits, and challenges of IBS application,

particularly in infrastructure projects. These findings should guide and assist

infrastructure project stakeholders to foresee upcoming opportunities and challenges

in implementing IBS in future infrastructure projects.

In conjunction with the Eleventh Malaysia Plan 2016-2020 (EPU, 2015b) to

strengthen the infrastructure provision, this study should benefit infrastructure

stakeholders in the Malaysian construction industry with their decision making by

considering various influencing factors more intuitively. At the same time, it provides

a better understanding of and helps to raise awareness among industry stakeholders

regarding the potential of IBS application as a sustainable construction method in

enhancing the sustainability of infrastructure projects. This responds to the CITP thrust

to make Malaysia infrastructure more sustainable and resilient (CIDB, 2015).

This research also proffers a framework for sustainable IBS application in

infrastructure projects. This study is unique in the context of the Malaysian

construction industry. The developed framework provides industry stakeholders with

a standard roadmap from holistic perspectives to assist them to make optimal decisions

about IBS application in future infrastructure projects. This framework can be used to

plan infrastructure project delivery and incorporate IBS as a construction method to

achieve more satisfactory performance of the project. As IBS is one of the sustainable

construction solutions, this framework is a direct response to the government

commitment of pursuing development (particularly in the construction industry) in a

more sustainable manner. This also relates to the CITP core initiatives to drive the

construction industry to adopt sustainable practices (CIDB, 2015). In the Eleventh

Malaysia Plan 2016-2020, responsibility for resource and energy-efficiency is one of

the main concerns in relation to intensifying the conservation of the environment and

natural endowment for future generations (EPU, 2015a). Therefore, the integration of

redevelopment consideration in the framework will consequently promote reservation

of natural resources depletion by maintaining consumed resources in a longer lifecycle.

In addition, the framework provides a series of practical strategies as a feasible

guideline to accommodate adaptability and changeability for future redevelopment. It


therefore creates a platform for further research and innovations to support these

strategies. Correspondingly, this relates to the CITP initiative to drive innovation in

sustainable construction (CIDB, 2015).

7.5 LIMITATIONS

Acknowledging limitations of research clarifies the context of the research

findings and provides a pathway for potential future research (Fellow & Liu, 2008).

The limitations of this research are listed below:

This study involved 20 participants and 15 panellists for interviews and a

Delphi study, respectively. The approached research participants were industry

professionals and academics with busy schedules; thus, obtaining their

agreement to participate was challenging. The number of participants for both

data collection mechanisms was limited due to the time constraint of the PhD

timeline. Although the number of interview participants is small, the in-depth

nature, as well as the selection of experienced experts from diversified

backgrounds, provided the wealth of information required for this study.

According to Malterud, Siersma, and Guassora (2016), if the participants are

highly specific with respect to the study aims, in addition to in-depth

exploration, 10 participants is deemed a considerable number. Furthermore, the

outcome of the interviews was further assured by the 15 expert panellists in the

Delphi study. The justification for the number of Delphi panellists was

provided in Section 3.7.2.

This research was conducted in Malaysia. The findings, especially from the

stakeholder perspective, were derived from the local construction industry.

However, these research findings can be extrapolated to other developing

countries with rapid infrastructure developments and IBS adoption. The lesson-

learned from this study can also provide a good source of exemplary references

for other developing countries.

It should be noted that the strategies provided in Section 6.5 purposely focus

on enhancing the effectiveness of IBS application to support changeability and

adaptability for infrastructure redevelopment. They do not include the generic

guidelines of IBS application at every phase of project execution.


There is also a limitation regarding the validation of the final framework

developed using qualitative research. Unlike quantitative research, this

research could not use sampling or statistical methods for validity purposes.

However, it should be noted that adoption of a Delphi study by its inherent

nature serves as a self-validating mechanism, because individual experts are

given chances to re-assess their scores with reference to the consolidated mean

scores as assessed by other experts. Moreover, triangulation of data was

adopted to cross-verify multi-sources of data, as a method of ensuring the

validity of this qualitative research.

There are also limits in relation to the ability to generalise the results of the

study due to the small-scale of a qualitative study. However, the strength of

constructivist research lies in its capacity to provide a wealth of insights, rich

detail, and thick descriptions (Jack & Anderson, 2002). Although participants

were drawn from a wide range of infrastructure stakeholders, their perspectives

were more reflective of building-type infrastructure. It must also be noted that

in some instances there was a limited amount of literature to support some

claims. However, the analysis presented was appropriately built upon the

relative theory or concepts from the relevant literature. It is hoped that these

insights will form the foundation of future research investigation in relation to

the different ways in which IBS can be efficiently adopted in infrastructure

projects.

7.6 RECOMMENDATIONS FOR FUTURE RESEARCH

This research provides further opportunities to explore IBS application in

infrastructure projects. Thus, there are some areas that can be further studied and

improved. The following recommendations can be considered as opportunities for

future studies:

To promote the uptake of IBS in infrastructure projects, this study has shown

the consideration factors for effective and efficient application. However, the

context of infrastructure projects mentioned during the interviews was not

conclusive. Further exploration of IBS application in specific types of built

infrastructure should also be undertaken. Each type has unique characteristics

in addition to its specific function. Different types of IBS would result in


different levels of changeability and adaptability. Thus, future researchers

should discover the capacity and limitation of each type of IBS to

accommodate these abilities. Moreover, it would be good to compare the

findings of this study with other sectors of the construction industry. Other than

that, there are research opportunities relating to components, connections, and

material innovation to enhance the effectiveness of IBS application.

This research was undertaken within the context of the Malaysian construction

industry, which represents a developing country. It is suggested that the

findings of this research should be tested or verified in different developing

countries in the Asian region to ensure its applicability. This may involve

several modifications to fit local preferences. Therefore, the outcomes could

perhaps represent the construction industry in a broader context. A comparison

study could also be conducted in different countries using a similar

methodology. The findings of this research can be used as a starting point for

a number of comparative studies between developing countries. It would be

meaningful for future researchers to discover insight from developed countries

by considering different policies, technology, and innovations, as well as other

specific local requirements. Lessons learned about the practices of developed

countries could serve as a model for better adoption in developing countries.

The interview results indicated that IBS remains an optional method in the

Malaysian construction industry. There are areas in which construction

practitioners remain sceptical about the effectiveness and efficiencies of this

method. The role played by each stakeholder should be explored in order to

create awareness and contribute to understanding of IBS implementation. At

the same time, the Malaysian construction industry needs to be guided to

increase its readiness to adopt and change to IBS. However, prior to this, a

study of the level of readiness of the local industry for IBS application needs

to be conducted to understand the level of awareness and readiness among

construction practitioners in Malaysia in terms of technology and expertise.

Appropriate training and research and development activities could then be

initiated to change the mindset of practitioners and advance the existing

technology, respectively.


It should be noted that the practical strategies provided in this research (see

Figure 6-5), as per the discussion in Section 6.5, were based on the

literature and were agreed to by the experts through the Delphi study. Further

research, such as a case study, could be conducted to determine the current

practices and the practical challenges of implementing the strategies.

Furthermore, by conducting a case study, the suggested strategies could be

verified, and their practicality validated.

This research was more focused on providing technical strategies for the

stakeholders to consider redevelopment potential. At some point, the

recommended strategies may indirectly influence decision making in other

segments, such as procurement systems, the selection of manufacturers, and

designer capabilities. In order to promote an effective implementation of

sustainable IBS in infrastructure projects, future research is recommended to

examine each construction phase (e.g., procurement, planning, design,

production, installation, operation, etc.) to explore and recognise the specific

concerns for each phase. Future research works could perhaps provide a more

comprehensive guideline for IBS application throughout the lifecycle of the

project phase. It would therefore be worthwhile to incorporate the framework

developed in this research into any future studies.

7.7 CONCLUDING REMARKS

This chapter compiled the review of the research objectives, key findings,

research contributions, limitations, and recommendation for future research.

This study found that IBS has sound potential in promoting construction

sustainability, regardless of the type of project. This research has developed a

framework of sustainable IBS application in facilitating redevelopment for

infrastructure projects. It demonstrates that incorporation of future redevelopment

consideration in infrastructure development could contribute to the sustainability of

infrastructure projects. Subsequently, IBS could facilitate built infrastructure

redevelopment works through adaptability and changeability. In order to enhance the

effectiveness of IBS application for the purpose of facilitating future redevelopment,

feasible strategies were provided as a guideline for construction practitioners.


As a concluding note, this research supports the government initiatives for

promoting IBS application in the Malaysian construction industry and providing more

resilient and sustainable infrastructure, as stipulated in Eleventh Malaysia Plan and

Construction Industry Transformation Plan 2016-2020 (EPU, 2015a; CIDB, 2015). It

is hoped that this will assist the local construction industry to move forward and

contribute to the continued growth and sustainability of the Malaysian construction

industry and further the national development. As quoted in the CITP:

The construction sector is becoming more important due to higher

demand for modern and efficient infrastructure in line with the aim of

becoming an advanced nation (CIDB, 2015).

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Appendices

Appendix A

Participant Information Sheet for Interview

272 Appendices

Appendix B

Sample of Consent Form

Appendices 273

Appendix C

List of semi-structured questionnaires

Main Questions Follow-up or sub-questions (if appropriate)

1. What is your understanding about Industrialised Building System (IBS)?

a. Could you tell me more about: • Panel system • Frame system • On-site fabrication • Sub-assembly & components • Blockwork system • Hybrid System • Volumetric/modular system

2. How IBS application contributes to sustainability or sustainable construction?

3. Is there any specific type of construction project suit well with IBS application?

a. Do you have an example to explain about that?

4. Do you think that IBS could be applied in infrastructure project like its application in building construction?

a. How will each of them perform then?

b. Do you think IBS is widely used in infrastructure development?

c. Do you find IBS implementation in infrastructure changed significantly in the last 10-15 years?

d. Based on current infrastructure development, should IBS application be considered in the infrastructure construction project?

e. Is there any specific type of infrastructure recommended for IBS application?

f. What kind of infrastructure suit with IBS application? Why?

g. Are there any requirement or policy in selecting construction method/approach in infrastructure development?

h. What are the criteria would be considered in selecting the type of construction method in infrastructure project?

5. Do you find any difference in determining the construction method between building and infrastructure construction?

a. Do you see any connection between IBS application in building project and infrastructure project? Why do you think this variation happened?

6. What are the factors that are causing the different level of IBS applicability between building and infrastructure?

a. Do you have an example to explain the difference?

b. Why IBS application seems familiar in building construction compared in infrastructure project?

c. Do you think IBS should be applied in infrastructure project? Why?

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Main Questions Follow-up or sub-questions (if appropriate)

d. What makes IBS preferred than conventional construction in infrastructure project?

e. What would be the advantage of employing IBS than conventional method?

7. Do you think IBS application could produce a sustainable building?

a. What makes you think so?

8. Do you think IBS application in infrastructure project could enhance the sustainability as it does in building construction?

a. To what degree you think IBS could improve the infrastructure project performance?

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Appendix D

Sample of Delphi Questionnaire Round One

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Appendix E

Sample of Delphi Questionnaire Round Two

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