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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 3-17: Items for Question 2 ............................................................................ 111
Figure 3-18: Items for Question 3 ............................................................................ 112
Figure 3-19: Items for Question 4 ............................................................................ 113
Figure 3-20: Items for Questions 5 and 6 ................................................................. 114
Figure 3-21: Items for Question 7 ............................................................................ 115
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,
Chapter 1: Introduction 3
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)
4 Chapter 1: Introduction
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)
Chapter 1: Introduction 5
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)
6 Chapter 1: Introduction
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
Chapter 1: Introduction 7
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-
8 Chapter 1: Introduction
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.
Chapter 1: Introduction 9
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.
10 Chapter 1: Introduction
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.
Chapter 1: Introduction 11
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
infrastructure sustainability.
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:
12 Chapter 1: Introduction
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.
Chapter 1: Introduction 13
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:
14 Chapter 1: Introduction
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
Chapter 1: Introduction 15
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.
16 Chapter 1: Introduction
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
Chapter 1: Introduction 17
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
18 Chapter 1: Introduction
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
Chapter 2: Literature Review 21
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.
22 Chapter 2: Literature Review
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
Chapter 2: Literature Review 23
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
infrastructure sustainability.
24 Chapter 2: Literature Review
Tab
le 2
-1: I
nfra
stru
ctur
e su
stai
nabl
e in
dica
tor
base
d on
pre
viou
s re
sear
ch
No
Au
thor
s S
ust
ain
able
In
dic
ator
/Att
rib
ute
Env
iron
men
t E
con
omy
Soc
ial
Eng
inee
ring
R
esou
rce
Uti
liza
tion
Hea
lth
&
Saf
ety
Pro
ject
M
anag
emen
t 1.
S
ahel
y et
al.,
(20
05)
• Con
stru
ctio
n m
ater
ial
usag
e • E
nerg
y us
age
• Lan
d us
e • W
ater
use
• C
onst
ruct
ion
was
te
• Loc
al a
ir p
ollu
tion
• G
HG
em
issi
ons
• Cap
ital
and
ope
rati
on a
nd
mai
nten
ance
cos
t • A
ffor
dabi
lity
/use
r fe
es/
serv
ice
fees
• E
xpen
ditu
re in
R&
D,
tech
nolo
gy c
hang
e • R
eser
ve f
unds
• A
cces
sibi
lity
•
Hea
lth
and
safe
ty
• P
ubli
c pa
rtic
ipat
ion
• C
apac
ity
• D
urab
ilit
y •
Fun
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
e • W
ater
• A
ir
• Noi
se
• Eco
logy
• V
isua
l im
pact
• W
aste
man
agem
ent
• Dir
ect c
ost (
init
ial c
ost,
life
cyc
le c
ost)
• I
ndir
ect c
ost (
rese
ttli
ng
cost
of
peop
le,
reha
bili
tati
ng c
ost o
f ec
osys
tem
, im
pact
on
tour
ism
val
ue, l
abou
r em
ploy
men
t)
• C
ultu
ral h
erit
age
• P
ubli
c ac
cess
•
Pub
lic
perc
epti
on
NA
• S
ite
acce
ss
• Mat
eria
l ava
ilab
ilit
y • T
ype
(pre
fabr
icat
ed/
inno
vati
ve m
ater
ial)
• C
onst
ruct
abil
ity
• Reu
sabi
lity
• Q
uali
ty a
ssur
ance
• Occ
upat
iona
l • P
ubli
c
• Con
trac
t and
pr
ocur
emen
t m
etho
d
3.
Fis
cher
& A
mek
udzi
(2
011)
• N
atur
al e
nvir
onm
ent
NA
•
Com
mun
ity
life
qu
alit
y •
Cul
ture
sen
siti
vity
•
Com
mun
ity
perc
epti
on a
nd
sati
sfac
tion
•
Hea
lth,
saf
ety
and
secu
rity
•
Pub
lic
atti
tude
and
li
fest
yle
NA
N
A
NA
N
A
4.
Fer
nánd
ez-S
ánch
ez &
R
odrí
guez
-Lóp
ez,
(201
0)
• Soi
l • W
ater
• A
tmos
pher
e • B
iodi
vers
ity
• Lan
dsca
pe
• Res
ourc
es
• Was
te
• Ene
rgy
• R
isks
• Cos
ts
• Tec
hnic
al r
equi
rem
ents
• B
urea
ucra
cy
• C
ultu
re
• A
cces
sibi
lity
•
Par
tici
pati
on o
f al
l ac
tors
•
Sec
urit
y •
Pub
lic
util
ity
• S
ocia
l int
egra
tion
•
Res
pons
ibil
ity
NA
N
A
NA
N
A
Chapter 2: Literature Review 25
No
Au
thor
s S
ust
ain
able
In
dic
ator
/Att
rib
ute
Env
iron
men
t E
con
omy
Soc
ial
Eng
inee
ring
R
esou
rce
Uti
liza
tion
Hea
lth
&
Saf
ety
Pro
ject
M
anag
emen
t 5.
W
ille
tts,
Bur
don,
Gla
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
•
Com
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
• Wat
er q
uali
ty
• Air
qua
lity
• N
oise
qua
lity
• E
colo
gy a
nd
biod
iver
sity
• V
isua
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
•
Cul
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
tion
ship
•
Inte
r-m
odal
ity
• S
ite
acce
ss/d
evel
opm
ent
• M
ater
ial t
ype
and
avai
labi
lity
•
Con
stru
ctab
ilit
y •
Reu
sabi
lity
•
Qua
lity
con
trol
/ass
uran
ce
• F
unct
iona
lity
, per
form
ance
of
phys
ical
ass
et
NA
• T
ype
of c
ontr
act
• Pro
cure
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
•
Leg
al
resp
onsi
bili
ty
• E
thic
al
resp
onsi
bili
ty
• P
olit
ical
re
spon
sibi
lity
NA
R
egu
lato
ry
Pro
ject
Sp
ecif
ic
Env
iron
men
tal
Tec
hnic
al
8.
Das
gupt
a &
Tam
, 200
5 • C
onfo
rman
ce to
a s
et o
f la
ws,
or
dina
nces
, reg
ulat
ions
and
sta
ndar
ds in
pr
e-pr
ojec
t pla
nnin
g, p
roje
ct
impl
emen
tati
on a
nd o
ngoi
ng o
pera
tion
s
• A
esth
etic
or
cult
ural
con
cern
s •
Con
trac
tual
lim
itat
ion
or p
roje
ct-
lim
itin
g cl
ause
•
Bus
ines
s-re
late
d is
sues
• H
uman
hea
lth,
wea
lth
and
poli
cies
•
Eco
logi
cal p
ress
ure,
sta
tus
and
resp
onse
s
• M
ater
ial a
nd e
nerg
y in
tens
ity
• M
ater
ial r
ecyc
led
inte
nsit
y •
Sol
id w
aste
gen
erat
ion
• E
mis
sion
inte
nsit
y •
Des
ign
life
26 Chapter 2: Literature Review
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
Chapter 2: Literature Review 27
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.
28 Chapter 2: Literature Review
(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.
Chapter 2: Literature Review 29
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.
30 Chapter 2: Literature Review
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
Chapter 2: Literature Review 31
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
32 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 33
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).
34 Chapter 2: Literature Review
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
Chapter 2: Literature Review 35
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
36 Chapter 2: Literature Review
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
Chapter 2: Literature Review 37
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
38 Chapter 2: Literature Review
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
Chapter 2: Literature Review 39
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
40 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 41
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.
42 Chapter 2: Literature Review
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-
Chapter 2: Literature Review 43
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
44 Chapter 2: Literature Review
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
Chapter 2: Literature Review 45
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.
46 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 47
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.
48 Chapter 2: Literature Review
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,
Chapter 2: Literature Review 49
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
50 Chapter 2: Literature Review
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
infrastructure development.
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
Chapter 2: Literature Review 51
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
52 Chapter 2: Literature Review
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
Chapter 2: Literature Review 53
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.
54 Chapter 2: Literature Review
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
Chapter 2: Literature Review 55
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
56 Chapter 2: Literature Review
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
Chapter 2: Literature Review 57
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
infrastructure development.
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
58 Chapter 2: Literature Review
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
Chapter 2: Literature Review 59
assessing the consideration factors, applicability and practicality of IBS in
infrastructure development.
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
60 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 61
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
62 Chapter 2: Literature Review
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
Chapter 2: Literature Review 63
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.
64 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 65
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
66 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 67
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
68 Chapter 2: Literature Review
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.
Chapter 2: Literature Review 69
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)
Chapter 3: Research Design and Methods 73
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
74 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 75
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
76 Chapter 3: Research Design and Methods
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)
Chapter 3: Research Design and Methods 77
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
78 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 79
Figure 3-6: Research process flowData Collection Method
80 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 81
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.
82 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 83
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
84 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 85
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
86 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 87
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
88 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 89
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).
90 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 91
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
92 Chapter 3: Research Design and Methods
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?
Chapter 3: Research Design and Methods 93
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.
94 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 95
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
96 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 97
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.
98 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 99
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,
100 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 101
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:
102 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 103
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.
104 Chapter 3: Research Design and Methods
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).
Chapter 3: Research Design and Methods 105
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.
106 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 107
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.
108 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 109
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”.
110 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 111
Figure 3-17: Items for Question 2
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
112 Chapter 3: Research Design and Methods
Figure 3-18: Items for Question 3
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
Chapter 3: Research Design and Methods 113
Figure 3-19: Items for Question 4
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
114 Chapter 3: Research Design and Methods
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)
Chapter 3: Research Design and Methods 115
Figure 3-21: Items for Question 7
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
116 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 117
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.
118 Chapter 3: Research Design and Methods
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.
Chapter 3: Research Design and Methods 119
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)
120 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 121
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.
122 Chapter 3: Research Design and Methods
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
Chapter 3: Research Design and Methods 123
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.
124 Chapter 3: Research Design and Methods
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 &
Chapter 3: Research Design and Methods 125
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.
126 Chapter 3: Research Design and Methods
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
11~20 5~10 Face-to-face
P14 Senior Manager Authority/
Government Agency
11~20 11~20 Face-to-face
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 129
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
130 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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)
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 131
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:
132 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
“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]
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 133
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]
134 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 135
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).
136 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 137
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.
138 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 139
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
140 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 141
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:
142 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
“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.
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 143
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)
144 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 145
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
146 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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.
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 147
“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
148 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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).
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 149
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.
150 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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).
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 151
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
152 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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).
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 153
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)
154 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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:
Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects 155
“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
156 Chapter 4: Understanding and Perception of IBS Application in Infrastructure Projects
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%
Chapter 5: Results of the Delphi Study 159
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
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160 Chapter 5: Results of the Delphi Study
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.
Chapter 5: Results of the Delphi Study 161
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
162 Chapter 5: Results of the Delphi Study
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.
Chapter 5: Results of the Delphi Study 163
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.
164 Chapter 5: Results of the Delphi Study
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
Project Characteristics
Industry Capacity
Consideration factors by category
Chapter 5: Results of the Delphi Study 165
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
166 Chapter 5: Results of the Delphi Study
Items IQR
Level of agreement (%) Reached
Consensus? Not Agree Agree
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
Chapter 5: Results of the Delphi Study 167
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
Clients Contractor Consultant Manufacturer Researcher
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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
168 Chapter 5: Results of the Delphi Study
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
Chapter 5: Results of the Delphi Study 169
Table 5-6: Rating results for the challenges of IBS application in infrastructure projects
Items IQR Level of agreement (%) Reached
Consensus? Not Agree Agree
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
170 Chapter 5: Results of the Delphi Study
Items IQR Level of agreement (%) Reached
Consensus? Not Agree Agree
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
Clients Contractor Consultant Manufacturer Researcher
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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
Chapter 5: Results of the Delphi Study 171
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
172 Chapter 5: Results of the Delphi Study
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
Level of agreement (%) Reached
Consensus? Not Agree Agree
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
Chapter 5: Results of the Delphi Study 173
Items IQR
Level of agreement (%) Reached
Consensus? Not Agree Agree
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.
174 Chapter 5: Results of the Delphi Study
Table 5-9: Mean ratings for the sustainability attributes of IBS by panellist subgroup
Items
All panellist
Clients Contractor Consultant Manufacturer Researcher
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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.
Chapter 5: Results of the Delphi Study 175
Table 5-10: Rating results for IBS adaptability criteria in facilitating infrastructure redevelopment
Items IQR Level of agreement (%) Reached
Consensus? Not Agree Agree
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
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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
176 Chapter 5: Results of the Delphi Study
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
Items IQR Level of agreement (%) Reached
Consensus? Not Agree Agree
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
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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
Chapter 5: Results of the Delphi Study 177
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
Items IQR Level of agreement (%) Reached
Consensus? Not important Important
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
178 Chapter 5: Results of the Delphi Study
Items IQR Level of agreement (%) Reached
Consensus? Not important Important
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.
Chapter 5: Results of the Delphi Study 179
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
Clients Contractor Consultant Manufacturer Researcher
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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
180 Chapter 5: Results of the Delphi Study
Items
All panellist
Clients Contractor Consultant Manufacturer Researcher
Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank Mean Rank
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-
Chapter 5: Results of the Delphi Study 181
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,
182 Chapter 5: Results of the Delphi Study
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
Chapter 6: Discussion 185
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
186 Chapter 6: Discussion
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
Chapter 6: Discussion 187
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
188 Chapter 6: Discussion
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).
Project Characteristics
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.
Chapter 6: Discussion 189
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 projects.
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
190 Chapter 6: Discussion
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
Chapter 6: Discussion 191
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).
192 Chapter 6: Discussion
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
Chapter 6: Discussion 193
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
194 Chapter 6: Discussion
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
Chapter 6: Discussion 195
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.
196 Chapter 6: Discussion
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
Chapter 6: Discussion 197
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
198 Chapter 6: Discussion
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
Chapter 6: Discussion 199
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
200 Chapter 6: Discussion
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
Chapter 6: Discussion 201
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
202 Chapter 6: Discussion
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.
Chapter 6: Discussion 203
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
204 Chapter 6: Discussion
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
Chapter 6: Discussion 205
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.
206 Chapter 6: Discussion
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
Product Industrialisation
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
Chapter 6: Discussion 207
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.
208 Chapter 6: Discussion
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.
Chapter 6: Discussion 209
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
210 Chapter 6: Discussion
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”.
Chapter 6: Discussion 211
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
212 Chapter 6: Discussion
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
Chapter 6: Discussion 213
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.
214 Chapter 6: Discussion
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
Chapter 6: Discussion 215
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,
216 Chapter 6: Discussion
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
Chapter 6: Discussion 217
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.
218 Chapter 6: Discussion
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
Chapter 6: Discussion 219
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
220 Chapter 6: Discussion
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
Chapter 6: Discussion 221
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.
222 Chapter 6: Discussion
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.
Chapter 6: Discussion 223
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224 Chapter 6: Discussion
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Chapter 6: Discussion 225
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
infrastructure projects.
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
Chapter 7: Conclusion 229
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
230 Chapter 7: Conclusion
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.
7.3.3 Research Question 2
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
Chapter 7: Conclusion 231
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.
7.3.4 Research Question 3
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
Project Characteristics
Design Requirement
Industrial Readiness Policy
• Requirement of project developer
• Requirement of government policy
232 Chapter 7: Conclusion
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
7.3.5 Research Question 4
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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Y
• 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
Product Industrialisation
• 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
S S
US
TA
IN
AB
LE
PE
RF
OR
MA
NC
E
IB
S S
US
TA
IN
AB
LE
AT
TR
IB
UT
ES
PR
OM
OT
ING
Chapter 7: Conclusion 233
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
infrastructure projects.
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-
234 Chapter 7: Conclusion
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).
Chapter 7: Conclusion 235
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
236 Chapter 7: Conclusion
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.
Chapter 7: Conclusion 237
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
238 Chapter 7: Conclusion
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.
Chapter 7: Conclusion 239
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.
240 Chapter 7: Conclusion
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 271
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?
274 Appendices
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?
Appendices 275
Appendix D
Sample of Delphi Questionnaire Round One
276 Appendices
Appendices 277
278 Appendices
Appendices 279
280 Appendices
Appendices 281
282 Appendices
Appendix E
Sample of Delphi Questionnaire Round Two
Appendices 283
284 Appendices