Production Engineering Division Board - IEI · Production Engineering Division Board About the Division Board The Institution of Engineers (India) has established Production Engineering

Production Engineering Division BoardAbout the Division Board

The Institution of Engineers (India) has established Production Engineering Division in the year 1984. This Division consists of quite a large number of corporate members from Government, Public, Private sectors, Academia and R&D Organizations.

Various types of technical activities organized by the Production Engineering Division include All India Seminars, All India Workshops, Lectures, Panel Discussions etc., which are held at various State/Local Centres of the Institution. Apart from these, National Convention of Production Engineers, an Apex activity of this Division is also organized each year on a particular theme approved by the Council of the Institution. In the National Convention, several technical sessions are arranged on the basis of different sub-themes along with two Memorial Lectures in the memory of “F W Taylor” and “G C Sen”, doyens in the field of Production Engineering, which are delivered simultaneously by the experts in this field.

In order to promote the research and developmental work taking place in the field of production engineering, the Institution also publishes Production Engineering Division Journal twice in a year, where mainly the researches and its findings are focused. Due to multi-level activities related to this engineering discipline, this division covers different sub-areas such as:

lLean ManufacturinglCellular Manufacturing (Biological Aspects)lDesign to Cost (DTC)lTotal Productive Management (TPM)lIntelligent ManufacturinglWeb-based ManufacturinglEnvironmental Issues in Production Engineering like Acoustics, Green House Effect, etc.lRapid PrototypinglNano-technologylProduct Life Cycle ManagementlSurface Engineering and Micro-machininglHuman Resources Technology (Management)lAdvanced Management SystemlEntrepreneurship and InnovationlIntegrated Information System (IIS)lProduction ManagementlWorkforce Participation / Involvement in ManufacturinglTQM and Quality SystemlCellular ManufacturinglDesign for Manufacturability (DFM) and Design for Quality (DFQ)lEnvironmental Issues in Production EngineeringlSustainable ManufacturinglAdvances in Precision ManufacturinglAdvanced processing of materials and compositeslGreen Power generationlSustainable ManufacturinglGreen ManufacturinglTechnology ManagementlInvolvement of Human Resource in Manufacturing Technology

In order to promote the research and developmental work in the field of Production Engineering, the Institution also publishes Journal of The Institution of Engineers (India): Series C in collaboration with M/S Springer which is an internationally peer reviewed journal. The journal is published four times in a year and serves the national and international engineering community through dissemination of scientific knowledge on practical engineering and design methodologies pertaining to Mechanical, Aerospace, Production and Marine engineering.

Message from the President

I am delighted to know that Production Engineering Division Board of the Institution has published its first Annual Technical Volume on the theme “Futuristic Manufacturing for Equitable Development in India”.

Its a matter of immense pleasure that the learned Corporate Members of the Institution attached to Production Engineering Division have contributed papers for this volume which are mainly from emerging fields of manufacturing including Lean and Agile Manufacturing, Rapid Prototyping and different non-conventional and eco-friendly approaches for manufacturing.

I must congratulate all Members of the Production Engineering Division Board for their sincere efforts and whole hearted support in bringing out this Annual Technical Volume. I am confident that the practicing professionals will be immensely benefited from this with the objective of improvement in manufacturing sector of India.

Mr H C S Berry, FIEPresident

The Institution of Engineers (India)

Message from Editor

It's a matter of immense pleasure to learn that the Production Engineering Division Board of The Institution of Engineers (India) has successfully brought out its first Annual Technical Volume as approved by CATE/Council. The theme of the said volume “Futuristic Manufacturing for Equitable Development in India”, is very pertinent in the present context of manufacturing industries. This volume consists of papers obtained from the Corporate Members attached to the Production Engineering Division of the Institution highlighted various aspects of topical interest in the field of manufacturing.

At this outset, I congratulate the Chairman and the Members of the Production Engineering Division Board for their sincere efforts in bringing out this exclusive collection of articles. I believe that this compiled volume will be helpful for the academicians and practicing professionals, which will stimulate further researches into this emerging field of technology.

Prof (Dr) N R Bandyopadhyay, FIE,Chairman

Committee for Advancement of Technology & Engineering (CATE)The Institution of Engineers (India)

Chief

Editorial

Business environment across the globe is becoming more and more competitive. Manufacturing is the most important competitive asset for an industrial organization. Those organizations that have recognized the need for innovations in manufacturing technology and processes as well as the development of human resources to gain access to knowledge have succeeded in the recent past.

It is indeed a matter of immense pleasure that the Production Engineering Division Board of the Institution, as per laid down norms by CATE/Council has published the first Annual Technical issue of production division on the theme 'Futuristic Manufacturing for Equitable Development in India', where the papers are included on contemporary issues and practical relevance to Indian Industry. I appreciate from my heart the endeavor taken by the Members of the Production Engineering Division Board including Prof. G. S. Dangayach, Dr. D K Tripathy and Dr. J Ramkumar, whose enthusiasm and initiative made it possible to bring out the publication. I specially thank Dr.D.K.Tripathy who is instrumental in bringing out this issue.

It is also a privilege for the Production Engineering Division Board that this Special issue has contributions from the professionals both from industry and academia. Hopefully this special volume is setting a new trend in Technical Publications of IEI and will become useful to larger cross section and the publication will be widely referred and quoted. I take this opportunity to congratulate and felicitate one and all associated with the publication.

I am confident that through this publication, the knowledge sharing and experience amongst engineering fraternity will result in better implementations of concepts with higher productivity.

Mr Ramesh Chandra Bairathi, FIEChairman

Production Engineering Division Board (PRDB)The Institution of Engineers(India)

.............Editorial

Business environment across the globe is becoming more and more competitive. Manufacturing is the most important competitive asset for an industrial organization. Those organizations that have recognized the need for innovations in manufacturing technology and processes as well as the development of human resources to gain access to knowledge have succeeded in the recent past.

It is indeed a matter of immense pleasure that the Production Engineering Division Board of the Institution, as per laid down norms by CATE/Council has published the first Annual Technical issue of production division on the theme 'Futuristic Manufacturing for Equitable Development in India', where the papers are included on contemporary issues and practical relevance to Indian Industry. I appreciate from my heart the endeavor taken by the Members of the Production Engineering Division Board including Prof. G. S. Dangayach, Dr. D K Tripathy and Dr. J Ramkumar, whose enthusiasm and initiative made it possible to bring out the publication. I specially thank Dr.D.K.Tripathy who is instrumental in bringing out this issue.

It is also a privilege for the Production Engineering Division Board that this Special issue has contributions from the professionals both from industry and academia. Hopefully this special volume is setting a new trend in Technical Publications of IEI and will become useful to larger cross section and the publication will be widely referred and quoted. I take this opportunity to congratulate and felicitate one and all associated with the publication.

I am confident that through this publication, the knowledge sharing and experience amongst engineering fraternity will result in better implementations of concepts with higher productivity.


Production Engineering Division Board (PRDB)The Institution of Engineers(India)

.............

PresidentMr H C S Berry, FIE

Secretary and Director General - I/C Dr Anil Kumar, FIE

Chief EditorProf (Dr) N R Bandyopadhayay, FIE,

Chairman, CATE

Consulting Editor Mr R C Bairathi, FIE,

Chairman,Production Engineering Division Board

Members of the Editorial BoardDr D K Tripathy, FIE

Dr G S Dangayach, FIEDr J Ramkumar, FIE

Dr Rajeev Agarwal, MIE

PublishersDr Anil Kumar,

Secretary and Director General - I/C for


Publication OfficeThe Institution of Engineers (India)

8 Gokhale Road, Kolkata 700020, Ph : 2223-8311/ 14-16/ 33-34,

Fax : (033) 2223-8345, e-mail : [email protected],

website : www.ieindia.org

Contents ......

The Institution of Engineers (India), 8 Gokhale Road, Kolkata 700020, as a body accepts no responsibility for the statements made by individuals in the paper and contents of papers published herein.

The Institution of Engineers (India) subscribes to the Fair Copying Declaration of the Royal Society. Reprints of any portion of the publication may be made provided that reference thereto be quoted.

As per Bye-Law 119, copyright of each paper published in Institution Journals or Proceedings in full or in abstract at its Centres shall lie with the Institution.

A Study on Laser Ignition

Pavithra H S, M G Anantha Prasad 7

Agile Manufacturing: Model and Manpower Challenges

A Khatri, D Garg, G S Dangayach 10

Application of a Hybrid Approach of Taguchi and TOPSIS for the Optimization of EDM Process Parameters for Al/SiCp-Metal Matrix Composite (20% SiC Reinforcement)

S Tripathy, A Rout, R Kumar, D K Tripathy 18

Experimental Investigation and Analysis for Selection of Rapid Prototyping Processes

V E Kothawade, A P Vadnere, S P Kakade 24

Futuristic Manufacturing for Equitable Development of India: Significance of Sustainable Manufacturing

P K Phukan 28

Green Production ¾ Concept for Future C K Roy 39

Lean, Agile and Le-agile Manufacturing

T K Roy 44

Nano-finishing of Freeform/Sculptured Surfaces: A Review

L D Nagdeve, V K Jain, J Ramkumar 50

Some Strategies for Achieving Green Manufacturing

U S Dixit 58

Annual Technical Volume of

Production Engineering Division BoardVolume I, 2016

Editorial Team

Technical Department, IEI

Mr S Chaudhury

Mr N Sengupta Mr K Sen Dr S Ghosh

Mr T Chakraborty Ms A Dutta Ms S Biswas Sett

Mr T K Roy Ms H Roy Mr S Bagchi

Mr P MukhopadhyayMs N Sikdar Mr P Mukhopadhyay

Printed at M/s New School Book Press, 3/2 Dixen Lane, Kolkata 700014

A Study on Laser IgnitionPavithra H S, Department of Mechanical Engineering, Dayananda Sagar University (DSU), Bangaloree-mail: [email protected], [email protected]

Abstract

Laser ignition has become an active research topic in recent years because it has the potential to replace the conventional electric spark plugs in engines compared to conventional spark ignition. Experiments with the direct injection engine have been carried out at the fundamental wavelength of the Nd:YAG laser as well as with a frequency doubled system. Experiments show that above a certain threshold intensity of the laser beam at the window even highly polluted surfaces could be cleaned with the first laser pulse which is important for operation in real world engines. The objective of this paper is to review past work to identify some fundamental issues underlying the physics of the laser spark ignition process and research needs in order to bring the laser ignition concept into the reality.

Keywords : Laser ignition; Spark ignition; Laser; Spark plug; Nd:YAG laser; Laser generation

M G Anantha Prasad

Introduction

The spark plug in SI engines has remained largely unchanged since its inventions, yet its poor ability to ignite highly dilute air-fuel mixtures limits the potential for improving combustion efficiency. SI also restricts engine design, since the spark position is fixed by the cylinder head location of the plug, and the protruding electrode disturbs the cylinder geometry and may quench the combustion flame kernel.

In this context, research into laser ignition seeks to examine its potential to improve combustion efficiency and stability compared to spark ignition by igniting highly dilute air-fuel mixtures with comparatively low ignition energies and to initiate ignition away from the (cold) walls of the combustion chamber. With recent advances made in laser technology, the range of laser ignition control parameters now includes laser pulse energy, pulse duration, wavelength, plus optical techniques and pulse selection for spatial and temporal distribution of laser in either single or multiple ignition events. The opportunity now exists to explore how the dynamic selection of these variables can be optimized for more efficient and cleaner combustion over the widest range of engine operating conditions.

Methodology

Lasers provide intense and unidirectional beam of light. Laser is monochromatic (one specific wavelength). Wavelength of light is determined by amount of energy released when electron drops to lower orbit. Light is coherent; all the photons have same wave fronts that launch to unison. Laser has tight beam and is strong and concentrated. To make

these three properties occur takes something called ‘Stimulated Emission’, in which photon emission is organized.

Principle of Laser Ignition

The laser beam is passed through a convex lens, this convex lens diverge the beam and make it immensely strong and sufficient enough to start combustion at that point. Hence the fuel is ignited at the focal point with the mechanism shown in Figure 1. The focal point is adjusted where the ignition is required to have.

Working Principle of Laser Ignition System

Laser ignition is the optical breakdown of gas molecules. A powerful short pulse laser beam is focused by a lens into a combustion chamber and near the focal spot a hot and bright plasma is generated. The laser ignition system has a laser transmitter with a fiber-optic cable powered by the car's battery. It shoots the laser beam to a focusing lens that would consume a much smaller space than current spark plugs. The lenses focus the beams into an intense pinpoint of light, and when the fuel is injected into the engine, the laser is fired and produces enough heat energy to ignite the fuel. The working principle of laser ignition system is shown in Figure 2.

Ignition in Combustion Chamber

The process begins with multi-photon ionization of few gas molecules which releases electrons that readily absorb more photons through the inverse bremsstrahlung process to increase their kinetic energy. Electrons liberated by this means collide with

7Annual Technical Volume of Production Engineering Division Board


8 Annual Technical Volume of Production Engineering Division Board


other molecules and ionize them, leading to an electron avalanche, and breakdown of the gas. Multi photon absorption processes are usually essential for the initial stage of breakdown because the available photon energy at visible and near IR wavelengths is much smaller than the ionization energy. For very short pulse duration (few picoseconds) the multi photon processes alone must provide breakdown, since there is insufficient time for electron-molecule collision to occur. Thus this avalanche of electrons and resultant ions collide with each other producing immense heat hence creating plasma which is sufficiently strong to ignite the fuel. The wavelength of laser depends upon the absorption properties of the laser and the minimum energy required depends upon the number of photons required for producing the electron avalanche.

Minimum Energy required for Ignition

The minimum ignition energy required for laser ignition is more than that for electric spark ignition because of following reasons:

(i) An initial comparison is useful for establishing the model requirements, and for identifying

Figure 2 Working of laser ignition system

Figure 1 Principle of laser ignition

causes of the higher laser MIE. First, the volume 3of a typical electrical ignition spark is 103 cm . -5The focal volume for a typical laser spark is 10

3cm .

(ii) Since atmospheric air contains 1000 charged 3particles/cm , the probability of finding a

charged particle in the discharge volume is very low for a laser spark.

(iii) The efficiency of energy transfer to near-threshold laser sparks is substantially lower than electrical sparks, so more power is required to heat laser sparks.

Advantages of Laser Ignition

(i) It does not require maintenance to remove carbon deposits because of its self-cleaning property.

(ii) Leaner mixtures can be burned as fuel ignition inside combustion chamber.

(iii) Lower combustion temperatures and less NOx emissions.

(iv) High pressure and temperatures do not affect the performance allowing the use of high compression ratios.

(v) Flame propagation is fast as multipoint fuel ignition is also possible.

(vi) Higher turbulence levels are not required due to above said advantages.

(vii) Lifetime is high.

(viii) Shorter ignition delay time and shorter combustion time.

(ix) Precise ignition timing is possible.

Drawbacks of Laser Ignition

(i) Higher laser intensities may induce material damage to various optical media used.

(ii) Dirt or changes in atmospheric conditions may damage the system.

(iii) Laser cannot tolerate vibrations.

(iv) Catastrophic damage may result from highly localized stress due to thermal shock, or self-focusing defects or ablation initiated by high field concentration at the site of surface imperfections and contaminations.

(v) During system maintenance or servicing assessment of the risk of accidently igniting flammables with concentrated levels of radiation would cause damage to personnel and environment.

Comparison between Laser Ignition and Spark Ignition

Another important question with a laser ignition

system is its reliability. It is clear that the operation of an engine causes very strong pollution within the combustion chamber. Deposits caused by the combustion process can contaminate the beam entrance window and the laser ignition system will probably fail. To quantify the influence of deposits on the laser ignition system, the engine has been operated with a spark plug at different load points for more than 20 h with an installed beam entrance window. As can be seen in Figure 2, the window was soiled with a dark layer of combustion deposits. Afterwards, a cold start of the engine was simulated. Already the first laser pulse ignited the fuel-air mixture. Further laser pulses ignited the engine without misfiring, too. After 100 cycles, the engine was stopped and the window was disassembled. As can be seen from Figure 1, all deposits have been removed by the laser beam. Additional experiments showed that for smooth operation of the engine, the minimum pulse energy of the laser is determined by the necessary intensity for cleaning of the beam entrance window. Estimated minimum pulse energies are too low since such ‘self-cleaning’ mechanisms are not taken into account. Engine operation without misfiring was always possible above a certain threshold intensity at the beam entrance window. The comparison between spark ignition and laser ignition systems is shown in Figure 3.

Future Prospects

Laser ignition offers a significant number of opportunities for improved combustion control in engines through a method of delivery of laser energy to focal positions, new generation laser parameters

and optical sensing. In order to fully exploit the benefits of laser ignition, these topics need further investigation before an optimized control scheme can be found. With proper control, these improvements enable engines to run under leaner conditions. The prospects of laser ignition are also particularly exciting from a control perspective. It is anticipated that this, combined with the capability to control the ignition location and timing, will play a significant role in optimization of future engines.

Conclusion

The applicability of a laser-induced ignition system on engine has been proven. Main advantage include almost free choice of the ignition location within the combustion chamber, even inside the fuel spray. Significant reductions in fuel consumption as well as reductions of exhaust gases show the potential of the laser ignition process.

At present, a laser ignition plug is very expensive compared to a standard electrical spark plug ignition system and it is nowhere near ready for deployment. But the potential and advantages certainly make the laser ignition more attractive in many practical applications

Acknowledgment

The authors grateful ly acknowledge the contributions of Mr Nagesh S T for his support and encouragement in the preparation of this document. Authors also gratefully acknowledge the moral support by Dayanand Sagar University, Bangalore.

References

1. G Liedl, D Schvocker, J Graf, D Klawatsch, H P Lenz, W F Piock, B Geringer. Laser Induced Ignition of Gasoline Direct Injection Engine.

2. B Chehroudi. Laser Ignition of Combustion Engines.

3. M Lackner, F Winter, J Graf, B Geringer, M Weinrotter, H Kopeck, E Wintner, J Klausner, G Herdin. Laser Ignition in Internal Combustion Engines.

4. V Sharma. Laser Spark Ignition in Lean Burn CNG Engine.

5. S S Harel, M Kharnar, V Sonawane. Laser Ignition System For IC Engines.

6. T Huges. Plasma and Laser Light, Adam Hilger, Bristol.

7. E Wintner. Laser Ignition.



Figure 3 Comparison laser ignition systems

between spark ignition and

Agile Manufacturing: Model and Manpower ChallengesA KhatriDepartment of Mechanical Engineering, Government Engineering College, Ajmer 305025, India, e-mail: [email protected]

D GargDepartment of Mechanical Engineering, National Institute of Technology, Kurukshetra, Indiae-mail : [email protected]

G S Dangayach Department of Mechanical Engineering Malaviya Institute of Technology, Jaipur, Indiae-mail : [email protected]

Abstract

The manufacturing system has become flexible and the organizations are using their manpower in flexible manner. In the present study, a conceptual agile manufacturing framework has been developed by the authors. The retention of employees is a big challenge for the organization when majority of employees seeks new job. Hire, retain and development of manpower are the main functions of human resource department. Agile manufacturing organizations are producing customized quality products in least time and for this, the multi disciplinary, self-organized and self-disciplined teams are deputed for the project and they have to work around the clock to achieve the target. In these projects, 100% devotion of employee is needed. So, the employee health and benefits become the responsibility of human resource department. This paper provides a broad line of actions to train, educate and develop the agile manpower in manufacturing industries and the challenges for agile workforce. The agile manufacturing framework has been developed by the author for better understanding the agile manufacturing systems.

Keywords : Manufacturing industries; Human resource development; Flexible manufacturing system; Agile manufacturing paradigm; Agile workforce; Agile manufacturing frame work.

Introduction

To fulfill the unique needs of customers, companies are becoming flexible and agile. To respond real time, they need to integrate agile supply chain. The concept of modular product has increased in the era of agility. The industrial environment has experienced a number of changes in present scenario. The demand becomes dynamic, the fashion and technology is changing rapidly and competitive companies are producing the product to beat the existing product.

The turbulent and dynamic factors have bound the companies to become agile. The agility becomes essential for the survival of companies in the competitive market. Profits in traditional products have shrinked due to competition, economic diversity, and social norms and changing fashion have change business environment. Global companies are now approaching different developing and under-developed countries to

promote their products as the market for customized product has emerged. Now the targets are beyond the reach of individual company, therefore they are adopting virtual enterprise concept.

Lindbergh, et al (1999) indicate that agility is made up of two components that are flexibility and speed. Essentially, an organisation must be able to respond flexibly and speedily. Agility incorporates speed and flexibility according to Kidd (1994). Terms such as speed, quick, fast and rapid are commonly used in the definitions of agility. Agility is the capabilities of an enterprise to reconfigure itself in response to sudden changes that are cost effective, robust, timely and of broad scope (Prince and Kay, 2003). Agility is dynamical specific change and growth oriented (Goldman, et al, 1995).

Agile manufacturing is essentially a set of abilities for meeting varied customer requirements in terms of price, quality, quantity, specifications and delivery



(Katayama and Bennett, 1999). Agile manufacturing is the ability of producing goods and services to operate profitably in a competitive environment of continuous and unpredictable change (DeVar, et a l, 1997). Agile manufacturing is the ability to accomplish rapid changeover from the assembly of one product to the assembly of many product (Quinn, et al,1997).

The flexibility is the basis for agility. Agile manufacturing is a manufacturing paradigm which considers agility a key concept necessary to survive in competitive market under an unexpectedly turbulent and changing environment (Gunasekaran, 1999).

The agile manufacturing would be the principal pattern of competitiveness for the smaller scale, modular production facilities, and cooperation between enterprises in the next generation (Goldman, et al, 1995; Sahin, 2000).

The environment, characteristics, capabilities and providers of agile manufacturing are shown in Table 1.

Agile organization is beneficial both for customer and organization. Agile organization is sensitive to change demand and reorients itself according to the current market needs. Agile organization can manage big projects with fewer resources.

Agile manufacturing systems require flexible manufacturing, virtual partners, supply chain partners, customer integrated multidisciplinary teams, computer integrated information systems and modular production facilities.

Agile Frame Works

Many frameworks of agile manufacturing have been developed by the researchers. The main conceptual frameworks have been summarised here.

Gunasekaran, et al (1999) introduced a framework for development of an agile manufacturing system. According to them strategies, technologies, systems and people are mainly four basic areas, one need to concentrate to become agile. The strategies can be further divided into virtual enterprise, supply chain and concurrent engineering. The technologies can be further divided into hardware and information technology. The systems included design system, production planning and control systems, and Data base management system. The people included knowledge worker, top management, training and education. The above areas can further classify into smaller sub-areas. Among the four pillars, the contribution of manpower is more than quarter.

Dove (1999) introduced agility framework on the aspect of knowledge management and change management and change proficiency. The framework was shaped like a balance, one side of which was change proficiency and on the other side it was knowledge management means agile CP/KM balance. Dove argued that dealing with change in competitive business is the key for success.

Meredith and Francis (2000) was proposed a wheel shaped reference framework of agility. It was comprised four main components namely, agile strategy, agile processes, agile linkages and agile people. Each component had four spokes. Agile

Table 1 Agile environment, characteristics, capabilities and providers

Agile Environment Agile Characteristics Agile Capabilities Agile ProvidersXCustomer make to order

requirement demand Responsiveness Concurrent EngineeringXShrinking profits XReady for change XFlexibility XInformation TechnologyXChanging social norms XJob enlargement and XData Interchange XSupply ChainXChanging fashion rotation XCollaboration XRapid PrototypingXMarket competition XUse of technological XRate of product XR&DXEconomy of diversity solutions introduction XAutomation andXInnovative technologies XWork standardization XRapid design and technologyXMarket opportunities XDelivering value to volume change XEnterprise integration XPolitical changes the customer XInnovation XRapid partnership XTechnological changes XValuing human XLearning organization formation

knowledge and skills XCost effectiveness XInterfacing with suppliers XForming virtual XProduct quality and customers

partnerships over life Multi skilled peopleXFitness for purpose XTeam workXAdaptive XDecentralized XCustomer relationship decision making

sales

X X X

X X

Sensitive to changed Delivery Speed Virtual Enterprise



strategy was sub-divided into : a wide deep scanning, strategic commitment, full development and agile scoreboard. Agile processes was sub-divided as flexible assets and systems, fast new product acquisition, rapid problem solving and rich information systems. Agile linkages was related to agility bench marking, deep customer insight, agile supplier and performing partnerships. Agile people were sub-divided into adaptable structure, multi skilled flexible people, rapid able decision making and continuous learning. The purpose of the wheel was to assist firms to audit their agile capabilities and plan accordingly.

Zhang and Sharifi (2000) proposed a conceptual framework of agility evaluation and implementation. According to them, agility need level can be determined on the basis of score of agile factors. They divided their framework in three basic areas namely, agility drivers, agility capabilities and agility providers. The degree of required agility was calculated on the basis of agility need level which is the function of business environment and turbulence. The gap between required agility and company's existing agility can be filled by agility providers.

Crocitto and Yusuf (2003) developed a framework ‘human side of organizational agility’. They emphasized on role of people in the organization, advanced manufacturing technology and organizational characteristics as key elements of success of organization. They concluded that Organizational agility as the function of quality, speed, cost and manufacturing agility.

Chin-Torng et al (2006) introduced a conceptual framework of agility enterprise. They shown agility enabler as a function of leverage people and information technology (foundation), master change and uncertainty (control) and collaborative relationships (strategy). According to them agility enabler is the building block of the agility. The agility capabilities shown in framework were flexibility, competency and quickness. The framework shown that market, technology, customer requirement, competitive criteria and social factors are the main agility drivers. They used fuzzy agility index (FAI) for each capabilities and fuzzy performance importance index (FPII) for each capability. They measure agility index for organization management, product design and product manufacturing. FAI score indicated the level of agility in the organization, which can further used for the self assessment and help in decision making.

Ramesh and Devadaran (2007) introduced a

framework based on 20 agile manufacturing criteria and concluded that agile manufacturing is the function of lean and flexible manufacturing. The twenty criteria used by Ramesh et al were organizational structure, status of quality, delegation of authority, manufacturing set ups, status of productivity, employee’s participation, employee’s status, nature of management, automation type, product life cycle, customer response adoption, product service life, production methodology, design improvement, manufacturing planning, cost management, information technology, change in business and technical processes, integration, time management and out sourcing.

Jafarnejad and Shanaie (2008) developed an organizational agility framework, according to which, the agility gap can be determined by the difference between desired and existing state. Existing state includes main organizational capabilities and human or generic indices, the desired state include agility drivers in external environment and dynamic or static state of internal environment. On the basis of identified gap, strategies and action plan can be designed and performance can be measured. According to author, evaluation of agility is a continuous process.

Vinodh et al (2010) introduced total agility design system (TADS) framework; they measured the agility on the basis of twenty criteria. The twenty criteria identified by them were organizational structure, devolution of authority, manufacturing set-ups, status of quality, status of productivity, employee's status, employee involvement, production methodology, nature of management, customer response adoption, product life cycle, product service life, design improvement, manufacturing planning, cost management, automation type, information technology integration, change in business and technical processes, time management and outsourcing. They distribute 1000 marks among twenty criteria and calculate agility index, arranging the formula for agility index AI = total score/1000. According to Vinodh et al (2010) organizations scored more than 500 are only eligible become to agile enterprise. Authors used fuzzy logic method to analyze the agility.

Some other frameworks from different researchers have also been introduced time to time. The different facets of agile manufacturing have been discussed by them but views of all of them are different. There are variety of technologies and management skills for achieving the agility. Agility drivers, capabilities and enablers are the main three components identified



Achieve agility byVirtual enterpriseConcurrent engineeringInformation technologySupply chain, tools technologyRapid prototyping People

by most of the researchers. Here flow diagram framework has been introduced considering these three components. A framework has been designed for achieving the agility focusing on the main components and their relationship among each other.

Achieving agility is not easy task. To measure agility of the firm, firstly analyze the firm’s capacities. A framework for dealing with a dynamic order and achieving the agility is shown in the Figure 1. Firm's capability to deal with agility depends on the delivery speed, responsiveness, flexibility to change, data interchange ability and collaborations of the organization. If the companies have the said parameters then only it can take the challenge to deliver a customized product. If the firm does not have the required capabilities then by integration of virtual manufacturing, concurrent engineering, information technology, supply chain management and rapid prototyping, it can achieve the agility.

Now, if a company achieves required agility then their higher management can take decision to make a customized product and give order to shop floor.

Gap in Agility

The difference between the desired and existing agility is the gap in agility. The agility provider can fill this gap and make the organization agile. If the company does not have the required agility then they have to take action to improve its agility, the top level management has to change its strategies. The agility providers are virtual enterprise, supply chain, concurrent engineering, information technology, manufacturing systems, people, tools and technology.

Virtual enterprise refers to the collaboration of variety of companies that share logically their own resources in order to design, develop a product and reduce product development cycle. Number of joint ventures worked successfully in India and around the world. They launch their product and achieve a great success. Virtual enterprise enables a company to produce huge product with limited recourses.It is also possible to have the manufacturing plant partly real and other part virtual (Shukla and Vazquez, 1996). The co-operation method, that is, virtual organization has increase the profit and help

Figure 1 Framework for achieving the agility

No Yes

Higher management decision

Shop floor order

Make to orderShrinking profits Changing social normsChanging fashionMarket competitionEconomy of diversityInnovative technologies

Have the

required

agility?

Agile environment/drivers

Delivery speed Responsiveness Flexibility Data interchange Collaboration

Evaluate the firm’s agility/agile capability



to achieve good business environment for the organization. Successful organisation of virtual enterprises results a new range of products.

Managing change in a manufacturing system requires a more systematic method of concurrently designing both the product and the down stream processes for production and other supports. This systematic approach is fundamentally known as concurrent engineering. According to Graham and Ragade (1994) the requirements for an intelligent concurrent engineering design support station which will allow the design engineer to evaluate design modifications while concurrently examining suitability and possibility for manufacturing.

Information technologies and technological tools such as internet, intranet, CAD, CAM, CIM, MRP, ERP, EDI etc can be employed to flow of the information in inter or intra perspective. The flow of information and technology strengthen an enterprise and make it capable to place at the top. The inter and intra flow of instructions are the backbone of the agility. Agile manufacturing needs intelligent sensing and decision making systems capable of automatically performing many tasks which were traditionally executed by human beings. The people include knowledge worker, top management, other all kind of worker and they play very important role in agility.

Role of People in Agile Manufacturing

People are one main pillar of agile manufacturing. Managing the human factor in a turbulent environment is quite difficult. The demand before work force is to achieve increasing levels of quality and flexibility with lower cost and shorter product life cycle. This unpredictable customer demand results work flexibly and use workforce in agile manner. Eisenhardt (1989) discussed that for the development of agile business practices, human factors should be takes into account, which affect decision making in the fast-paced dynamic environment.

Agile manufacturing can be operated effectively with the help of knowledge workers such as computer operators, draftsman, computer engineer, design engineers and maintenance engineers. Since agile manufacturing is more information technology intensive so, there is need to improve the productivity of knowledge workers with the objective to achieve agility in manufacturing.

The most critical problem in agile environment is how to manage and motivate workforce to support the flexibility and responsiveness. When information

does not flow in the system, due to technical or human issues the agility will lost. For this reason, elimination of human points of failure in infrastructure support is essential (Forsythe, 1996). Systems and technologies can easily be purchased but it is difficult to manage workforce. According to Allen (1997) human factor will not only play a vital role in accomplishing the technical and social objectives of agile manufacturing but have an opportunity to participate in sharing the evolution of industry paradigms for the next century.

Employee management is first concern for an organization. Effective management and leadership of employees plays important role in achieving the goals. Effective employee management and leadership allow capitalizing on the strengths of other employees and their ability to contribute to achieve the work goals. Successful employee management and leadership promote employee engagement, employee motivation, employee development, employee satisfaction, employee retention and the accomplishing of goals.

To achieve agility one need flexible and dedicated workforce who can work in a team. So the manpower required in agile manufacturing is somewhat different and dedicated therefore the role of human resource development (HRD) becomes quite important. Each employee is required to view and understand his work in terms of the whole rather than the part according to Yusuf (1999). Forsythe (1997) discussed human factors in context of infrastructure and communications.

Challenges to HRD in Agile Organizations

The biggest challenge organizations facing is the development of competent, forward looking and effective human resource. Superior human resource is a critical part in any business or organization and determines the performance of any organization. The structure of human resource and the way it operates is crucial in helping businesses and organization to run efficiently. No matter how much an organization spends in capital, human resource remains the key determinant of an organization's success. This is because the quality of human resource directly influences the quality of goods or services. Organizations therefore, have an obligation to ensure their personals get continuous exposure to information and skills that can better their performance. HRD includes any effort that provides learning and training opportunities to teams and individuals within organizations, in order to improve their performance. This is achievable through



strategies, programs and policies, for training and development to counter the challenges that administrative staff is facing globally. The main manpower challenges which organizations are facing are as follows:

Selection/Recruitment of Right Person

Since the HRD have to select qualified potential agile manpower therefore filtering of capable person starts from the short listing of applications. Selecting the best applicants for an interview is like a crap shooting. Conducting a legal interview to select the best candidate for required position is very important. The interview plays significant role in hiring and is a powerful tool and process to evaluate candidates. The person or employee who is good for one industry is not necessarily suitable for the agile industry. The dedication and honesty are more important for agile manpower.

Training of Employees

How a new employee is welcomed into the organization is critical. Employee orientation process forms the foundation for a successful employment relationship. Effective ongoing training and development, whether it is in the classroom or on-the-job, ensures employee success in his current position. Effective employee training and d e v e l o p m e n t g u a r a n t e e s f o r a c h i e v i n g organisational targets.

Employees are developed and educated through training classes, workshops, conferences and seminars etc. The main important responsibilities of HRD are coaching, training, mentoring, and building the organization into a learning organization. It is to be ensured that the programmes are designed on the basis of systematically identified training needs. Companies have to build evaluation mechanisms or performance indicators at regular intervals.

Training and staff development ensure that the workforce will continue to develop the skills necessary for success at present and in the future too. Effective needs assessment, training provision, training transfer, training scheduling and training design provide the necessary framework for successful training programmes in the organization. Aside from experience, training is the most important way of acquiring skills and knowledge. Training is an effective way of changing attitudes and increasing personnel motivation.

Top Management Support

The top management vision and mission should be

transperant about agility, their willingness is very important. Since achieving agility in manufacturing require critical changes in the line of reengineering business process. This level of change in any organization needs a total support of top management in terms of technical and financial aspects. Agility requires reengineering of strategies, systems, technologies, and people. The industry cannot be run only by finance. The proper strategies gave success to the industries, especially HRD needs support from top management for providing more facilities and other allowances required for manpower.

Employees Continuous Learning

The employee can only developed to its fullest if gets continuous learning. Most of the companies provide training to their employees but it is not enough as the technology and tool advances day by day, therefore when the employees are not in the process of continuous learning, they will face problems not today but tomorrow which in turn creates barrier to the human resource development and also makes the employees less motivated. The learning is a continuous life long process, person who is learner achieves his target easily. Learning with fun is better way for employees therefore organizations are providing training at good pick nick spots so pleasant environment may be available to their employees. Classroom and on board both the training are very important. Organizations try to improve the performance of their employees by all means of training.

Performance Management

Performance management includes employee performance improvement, employee assignment, c h a l l e n g i n g a s s i g n m e n t s , p e r f o r m a n c e development, training, cross-training, 360 degree feedback and regular performance feedback. The annual review and evaluation is carried by the managers. The appraisal of employees depends on their annual performance. In agile industries, work is performed by the teams so the assessment becomes more difficult for the managers.

Change Management

Change management is a crucial skill for a manager in a work environment that is constantly changing and also difficult to manage. To manage change, address employee resistance to change, and to ensure company’s goals are main role of managers. Change management is a skill that is worth your time to develop. Agile work force should always be ready for



change. As today’s market is quite dynamic and changing very fast, at this outset, it is very difficult for the manager to manage work force. Resistance to change is quite obvious and addressing the employee for the change, that require managerial and leadership skills.

Conflict Management

In addition to professional knowledge and expertise, managers also need conflict resolution tacts. Conflict resolution skills like mediation and arbitration will strengthen the ability to cope with the daily challenges of a contemporary workplace. They will also increase motivation and commitment to the work. In Agile teams many times egos of employee's clashes and handling the situation becomes difficult, in these situations the role of managers becomes more critical.

Retention of Employees

Employee retention, especially of your good, best, most desirable employee is a key challenge in organizations. The HRD should know tips, tools and ideas of employee retention loyalty strategies. Promotions, appraisals, motivate an employee to work in the organization are the main techniques of it. In Agile industries the retention becomes more challenging for the managers. Since the working style is some what different then other type of manufacturing industries.

Lack of Funds for HRD

Now days it has been observed that some companies are reducing their budget day by day for the human resource development and they are spending more on capital investment and management, asset management, fund management, research and development and market research. Human factors are considered by all the organization but what extent they are focusing on it is the matter of concern. The basic facilities are provided by all the organizations but training, leave, special leave, entertainments, employees’ satisfaction etc are making difference.

Lack of Educational Advancement

Most of companies are not sponsoring the employees for higher qualification. Most of the employees are not getting special leave to upgrade their educational qualification. This creates a barrier for the human resource development and the employees have to leave their job in order to upgrade their educational qualification in order to get promoted and to acquire higher position in the organisation. For any position

the minimum educational qualification is always one essential requirement. Employee who seeks to acquire higher qualification should be encouraged by the organization since these employees will be the assets for them in future.

Healthy Work Environments

Healthy work environment is the one motivating factor for employee. If one have less salary but getting healthy work environment and satisfaction then person will be retained in organization without any hesitation and give its full contribution. The organizations should aware about stress management, time management, safety, work-life balance, workplace security and housekeeping, burnout, coping, job sharing and other creative scheduling arrangements, and employee wellness. This will be possible when the HRD works on it and identify all factors or engagement, motivation and contribution. To maintain high morale especially when people works for long hours then the employees rewarding and refreshment packages plays good role.

Employee Motivation and Rewarding

Keep manpower engaged, motivated to work and contribute in the growth of organization is very important. Employee motivation, training and development, employee engagement, positive employee morale, rewards and recognition are responsibilities of HRD. Company’s reward and reorganization system should be promising to employees. Reorganization of both formal and informal employees is quite important. Rewarding and thanking the employees is an art of management and how they implement it in their organization is matter of concern.

Conclusion

The flow of information, technology, people, virtual enterprise and reconfiguration are the keys of agile manufacturing. This paper emphasized on the environment responsible for companies to become agile. Agile environment, characteristics, capabilities and providers have been tabulated. The identification of gap to be agile and required steps towards agility has been discussed. A high level integration is required inside and outside of the organization; automation at all levels is also required but this one step can take company miles ahead to others. The framework gave the full pathway towards the agility, the framework clearly show all the factors of agility and their relationship among each other.

The role of manpower and challenges to agile



manpower also has been discussed in this paper. The practice for improving the expertise of individuals include all level of employees, teams, work processes, and the overall organization is quite important in agile manufacturing. This paper reveals the manpower challenges of HRD in context of agile manufacturing. The manpower required in agile enterprises and their development is quite challenging.

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Application of a Hybrid Approach of Taguchi and TOPSIS for the Optimization of EDM Process Parameters for Al/SiCp-Metal Matrix Composite (20% SiC Reinforcement) S Tripathy, A Rout, R Kumar Mechanical Engineering Department, Institute of Technical Education and Research (ITER)Siksha 'O' Anusandhan University Jagamara, Khandagiri, Bhubaneswar, Odisha, Indiae-mail: [email protected], [email protected],[email protected]

D K TripathyKalinga Institute of Industrial Technology University, Bhubanesware-mail:[email protected]

Abstract

In this study, machining of Al, SiCp-metal matrix composite (with 20% SiC reinforcement) is done by EDM. Al, SiCp-MMC is a hard and light weight material which has a wide range of application in aerospace and automobile engineering. The objective of present work is to study the effect of input current (Ip), gap voltage (Vg), duty cycle (t) and pulse-on-time (t) on metal removal rate (MRR), tool wear rate (TWR), diametric overcut (Z) and surface roughness (Ra) on electric discharge machining of Al, SiCp-20% SiC reinforcement. Brass rod of 15 mm diameter was selected as the tool electrode. An L9 orthogonal array (OA) of three levels was opted for the experiment. The optimum set of input parameters was obtained by using technique for order preference by similarity to ideal solution (TOPSIS) to get maximum MRR, minimum overcut, TWR and Ra.

Keywords : EDM; Al; SiCp-metal matrix composite (with 20% SiC reinforcement); MRR; TWR; Overcut; Surface roughness; TOPSIS.

Notations

D Decision matrixm

d Diameter of the machined area, mmm

d Diameter of the tool, mmt

Ip Input current, A3MRR Metal removal rate, mm /min

r Normalized matrixij

Ra Surface roughness, mm+S Euclidean distance from ‘ideal’ solution-S Euclidean distance from ‘negative ideal’

solution

t Machining time, min

ton Pulse-on-time, µs

T Final weight of the tool, gmf

T Initial weight of the tool, gmi3TWR Tool wear rate, mm /min

v Weighted matrixij

Vg Gap voltage, V+V Ideal solution

-V Negative ideal solution

W Final weight of the workpiece, gmf

W Initial weight of the workpiece, gmi

Z Diametral overcut, mm3rDensity of tool, gm/mmt

3rDensity of the workpiece, gm/mmw

tDuty cycle

Introduction

In this constantly evolving world, the need of materials with characteristics such as light weight and high strength is rapidly increasing in technological field. As a result of this evolution efforts are focused on aluminium based metal matrix composite as they possess the required characteristics. Metal matrix composites is a composite which constitutes of at least two components out of which one should be metal and the other component may be a metal or other material such as ceramic or organic compounds. In



this study Al, SiCp-MMC (20% SiC reinforcement) was selected as the work piece material. Basically aluminium is a light weight, low melting point and low strength material whose properties are e n h a n c e d by 2 0 % s i l i c o n c a rb i d e ( S i C ) reinforcement [1-4]. While machining by these conventional processes it causes high tool wear and high tool cost is required [5]. Al, SiCp-MMC can also be machined by non conventional machining processes as it offers non contact material removal processes [6] and are used where better surface finish and high dimensional accuracy are required , among which electric discharge machining (EDM) is considered as an effective method for machining c o m p o s i t e s [ 7 - 1 0 ] . E D M i s o n e o f t h e nonconventional machining processes which is used to machine materials which are hard to be machined by conventional processes.

It was observed from the literature survey that not much work has been done on Al, SiCp MMC with 20% SiC reinforcement and it specifically used to make parts of high speed motors. The objective of the present work is to study the effect of input current (Ip), gap voltage (Vg), duty cycle (t) and pulse on-time (t) on metal removal rate (MRR), tool wear rate (TWR), electrode wear ratio (EWR), diametric overcut (Z) and surface roughness (Ra) on electric discharge machining of Al, SiCp-20% SiC reinforcement and finding the optimum set of input parameters.

Experimental Method and Procedure

Method of Preparation of Al, SiC-Metal Matrix Composites

Al, SiCp-MMC consists of pure aluminium and silicon carbide particles (less than 75µm particle size). Metal Matrix Composites can be prepared by various fabrication techniques such as pressing and sintering method, forging and extrusion method, vortex and Stir-casting method. Among the processes, the work piece Al, SiCp-MMC was prepared by stir casting process. Brass tool of diameter 15 mm was selected as the tool electrode.

Machining and Response Parameters

For the experimental procedure, four machining parameters were selected such as input current (Ip), pulse-on-time (t), duty cycle (t) and gap voltage (Vg) along with their three levels as shown in Table 1.

L9 orthogonal array (OA) was obtained using Taguchi model [12]. It was used to perform the experiment as shown in Table 2 and four output response

parameters were studied such as metal removal rate (MRR), tool wear rate (TWR), diametric overcut (Z) and surface roughness (Ra).

Nine experiments were carried out and for each trial, the weight of the work-piece and tool before and after machining was calculated and were used to determine MRR, TWR, EWR and diametric overcut using the following formulas.

MRR is defined as the difference in weight before and after machining of work piece per unit machining

3time and it is expressed in terms of mm /min

(1)

TWR is defined as the difference in the weight of the tool before and after machining per unit machining

3time and it is expresses in terms of mm /min

(2)

Z is defined as half of the difference between the diameter of machined area and the diameter of the tool.

(3)

The values of MRR, TWR, overcut and surface roughness found in the experiment by varying the input parameters such as input current, pulse-on-time, duty cycle and gap voltage as shown in Table 3.

Table 1 Levels of parameters

Machining Level-1 Level-2 Level-3ParametersInput current, A 3 5 7Pulse-on-time, µs 50 75 100Duty cycle 7 8 9Gap voltage, V 30 40 50

Table 2 L9 experimental plan

Input Pulse-on- Duty Gap Current(Ip) Time (ton) Cycle(t) Voltage(Vg)

3 50 7 303 75 8 403 100 9 505 50 8 505 75 9 305 100 7 407 50 9 407 75 7 507 100 8 30



Proposed

The different performance parameters of EDM are influenced by the process parameters differently. So to arrive at the best combination of process parameters for the machining of Al, SiCp MMCs a multi-objective optimization technique need to be adapted so that both quality and profit can be achieved [9-11]. For this technique for order of preference by similarity to ideal solution (TOPSIS) has been utilized which is one of the most simple and efficient multi-optimization technique used to find the best alternative from a finite set. The different steps for obtaining the optimal setting of process parameters have been described as follows [13-16]:

Step-1 Decision matrix is the first step of TOPSIS which consist of ‘n’ attributes and ‘m’ alternatives which is represented as:

(4)

where x is the performance of ith alternative with ijrespect to jth attribute.

Step-2 Normalized matrix is obtained from the following expression

(5)

Step-3 The weight of each attribute was assumed to be w (j = 1,2,....,n). The weighted normalized decision j matrix V=[ v ] can be obtained byij

V= w r (6)j ij

where

Methodology for Optimization Step-4 In this step the ideal (best) and negative-ideal (worst) solutions were obtained from the following expression

(7)

(8)

Step-5 In this step the separation between alternatives were determined. The separation of each alternative from 'ideal' solution is given by

(9)

The separation of each alternative from ‘negative-ideal’ solution is given by

(10)

Step-6 In this step the relative closeness of particular alternative to the ideal solution is calculated which is expressed as

(11)

Step-7 Ranking has been given according to the values of P . The highest value of P has been given as ithe first setting and the corresponding set of process parameters is set as the most optimal one.

Results and Discussion

Effect of Current, Pulse-on-Time and Gap Voltage on MRR

Figure 1 shows the variation of MRR with input parameters. It was observed that with increase in input current, MRR increases, with increase in Pulse-

i



Table 3 Experimental data for different input parameters

Input Pulse-on- Duty Gap MRR, TWR, Overcut, Surface3Current (Ip), A Time (t), µs (t) (Vg), (V) mm /min mm /min mm Roughness(Ra)

3 50 7 30 1.1849 1.2689 0.13 2.1243 75 8 40 0.7255 1.7087 0.07 1.93 100 9 50 0.8429 1.7508 0.04 2.685 50 8 50 4.7655 2.7008 0.1 2.65 75 9 30 3.5944 2.6278 0.025 2.865 100 7 40 5.7816 3.5317 0.01 3.347 50 9 40 7.8961 2.1349 0.025 2.087 75 7 50 6.6114 2.6889 0.06 3.447 100 8 30 7.2909 3.2913 0.015 6.2

Cycle Voltage3

on-time MRR first decreases and after reaching certain value it starts increasing and with increase in gap voltage MRR first increases and after reaching certain value it starts decreasing.

Effect of Current, Pulse-on-Time and Gap Voltage on TWR

The variation of tool wear rate found in the experiment with the input parameters such as input current, pulse-on-time and gap voltage as shown in Figure 2.

It was observed that with increase in input current,

TWR increases, with increase in pulse-on-time

initially TWR decreases up to certain value then it

increases and initially with increase in gap voltage

TWR increases up to a certain extent and then there is

decrease in TWR.

Effect of Current, Pulse-on-Time and Gap Voltage on

Surface Roughness

The variation of surface roughness found in the

experiment with the input parameters such as input

current, pulse-on-time and gap voltage as shown in

Figure 3.

Figure 2 Effect of input parameters on TWR

Figure 3 Effect of input parameters on surface roughness

Figure 1 Effect of input parameters on MRR



It was observed that with increase in input current, surface roughness increases, with the variation of pulse-on-time with surface roughness remains constant up to certain level then it rises suddenly and with increase in gap voltage, surface roughness decreases up to certain level then it remains constant.

Application of TOPSIS Method

The decision matrix and corresponding weighted normalized matrix have been calculated utilizing equations (5)-(7) as shown below.

(12)

(13)

The separation measures from the ideal solutions have been evaluated. Finally the closeness coefficients and their ranking have been performed as described in methodology and shown in Table 4.

The seventh number of run has been selected as the optimal setting of process parameters to get the best output. The corresponding values of process parameters are shown in Table 5.

Confirmation Test

After getting the optimum set of input parameters through TOPSIS, again machining was carried out with the same set of input parameters and MRR, TWR, EWR, diametral overcut and surface roughness were again calculated which was found to be approximately same as the previous values.

Conclusion

After conducting the experiment on AlSiC-Metal Matrix Composite, the important conclusions are as follows:

lThe feasibility of machining AlSiC-MMC (20% SiC reinforcement) by EDM was evaluated.

lThe optimum set of input parameters was found to be high level of input current, low level of pulse-on-time, high level of duty cycle and intermediate level of gap voltage.

lFor the optimum set of input parameters, MRR was found to be the maximum value and TWR, overcut and surface roughness found to be closer to the minimum value.

lTOPSIS method along with Taguchi design of experiment have been utilized successfully to obtain efficient way for machining of these difficult to machine Al, SiCp- MMCs.

References

1. R Dasgupta. Aluminium Alloy-based Metal Matrix Composite: A Potential Material for Wear Resistant Application, International Scholary Research Network, 2, Article ID 594573, 2012

2. S Kumar, V Balasubramanian. Effect of Reinforcement Size and Volume Fraction on Abrasive Wear Behavior of AA7075 Al/SiCp P/M Composites ¾ A Statistical Analysis, Tribology International, 43, 414-422, 2010.

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4. S Das, R Behera, G Majmudar, B Oraon, G Sutradhar. An Experimental Investigation on

Table 4 Calculated values of separation measures, closeness coefficients and corresponding ranking

+Run Si

1 0.188552 0.122509 0.393843 92 0.141193 0.142067 0.501543 73 0.124549 0.153812 0.552562 64 0.134334 0.119798 0.4714 85 0.087783 0.166139 0.654293 36 0.085973 0.187554 0.685688 27 0.082548 0.190356 0.697519 18 0.088695 0.150312 0.628901 49 0.123345 0.182076 0.596147 5

-S P Ranki i

Table 5 The optimal setting of process parameters

Input Pulse-on- Duty GapCurrent ( Ip) Time(ton) Cycle (t) Voltage (Vg)

7A 50 µs 90% 40 V



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Electrical Discharge Machining, International Journal of Engineering Science and Technology, 3 , 87-101, 2011.

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Experimental Investigation and Analysis for Selection of Rapid Prototyping ProcessesV E Kothawade, A P Vadnere, Department of Mechanical Engineering, Mumbai Educational Trust’s Institute of Technology Polytechnic, Nashik, Indiae-mail: [email protected], [email protected], [email protected]

Abstract

Selection of correct and optimize way of the prototype manufacturing is one of the immense important requirement for manufacturers. Increasing demand of rapid prototyping (RP) variants makes this selection procedure more complicated and requires greater expertise involvement and hence takes more time. Eventually the selection is based on the previous records and performance of the available method with some suggestions from the expertise. This paper propose the way of selection of rapid prototyping methods with reference to part requirement such as surface finishing, accuracy, build time, tensile strength, cost. The study reveals the part and process requirement for efficient and economical output through prototype manufacturing. Such process selection creates criteria for conflict free decision making which routes to the minimization of prototype manufacturing lead time. It utilizes the analytical hierarchical process (AHP) which is a well known theory of measurement through pair wise evaluation and priority scale given by expertise along with the grey relational analysis (GRA) to establish an accurate and correct hypocritical model which decides priority of the methods which can be implemented. Process selection will help in systematic and analytical manner to address every element of selection - complexity due to interrelation of attributes, wide range of Rapid Prototyping alternatives available, variety of Rapid Prototyping application areas, and expertise requirement.

Keywords Analytical hierarchical process (AHP); Grey relational analysis (GRA); Part requirements; Rapid prototyping applications; Selection of rapid prototyping methods.

S P Kakade

Introduction

Any organization in current era is trying to sustain in this immense competitive business through product development and modification. This modification leads to change in design, change in aesthetics or complete product change. For such changes the organization must ensures the available resources capability and their vendors capacity to accommodate the change. The special tooling requirement for manufacturing, another inspection media required or not, capability of existing machinery to accommodate the changes in the product can be easily visualized with the help of available physical model, that is, prototype. Wide variants are available to manufacture the prototype in rapid prototyping methods. Selection of the correct method is very complex and requires more time. Appropriate technology selection is difficult, multitasking and complex process. The best process selection depends upon many attributes which are many times interrelated to each other. It is a complex problem that can not be solved readily using conventional statistical techniques alone. Selection

of an appropriate process requires a sound understanding of the interactions between the part quality, part properties, part cost, build envelope, build time (speed) and other concerns [1]. Process selection will help in systematic and analytical manner to address every element of selection-complexity due to interrelation of attributes, wide range of RP alternatives available, variety of RP prototype application areas, and expertise requirement [2].

Literature Review

Masood et al [3] developed the IRIS system selector following the methodology which accepts inputs and commands to produce a search reports detailing a most appropriate RP system. Shende et al [4] studied the part requirement to generate the feasible alternative process and after evaluation of data with graph theory, matrix approach and TOPSIS method they proposed the decision support system. Byun and Lee [5] proposed the methodology which deals with selection of optimal RP system using modified TOPSIS method. Shaharbi and Javadi [6] presents combined methodology for identification,

comparison, and selection of RP system using AHP and modified TOPSIS method. Panda et al [7] uses Integrated AHP and fuzzy TOPSIS approach for the selection of RP process under multi criteria perspective. Peres and Martin [8] Introduced and discussed the problematic about intersect of implement of concurrent engineering and selection of RP process suggesting design methods and focus on relevant RP technologies and practical case studies.

Methodology

In this paper, for calculation of weightage of each defined criteria AHP and to find the rankings of RP methods GRA is selected. The methodology is described as follows.

Definition of Criteria for Method Selection

The first step of method evaluation is to define a criteria or factor on the basis of which the performance of method is to be evaluated [9].

Finding of Weights of Defined Criteria by AHP

The analytic hierarchy process (AHP) is a theory of measurement through pair wise comparisons and relies on the judgments of experts to derive priority scales. It is these scales that measure intangibles in relative terms[9].

Construct a pair-wise comparison matrix using a scale of relative importance. The judgments are entered using the fundamental scale of the AHP. An attribute compared with it is always assigned values 1. The numbers 3, 5, 7, and 9 correspond to the verbal judgments ‘moderate importance’, ‘strong importance’, ‘very strong importance’ and ‘absolute importance’ (with 2, 4, 6, and 8 for compromise between these values). Assuming M attributes, the pair-wise comparison of attribute i with attribute j yields a square matrix B=M M where aij denotes the comparative importance of attribute i with respect to attribute j. In the matrix, bij = 1 when i = j and bji = 1/bij. Find the relative normalized weight (wj) of each attribute by,

(i) Calculating the geometric mean of the ith row. The pair-wise comparison matrix is shown in Table 1;

(ii)Normalizing the geometric means of rows in the comparison matrix:-

This can be represented as below,

and

After computing the weights the consistency of weights were checked [9]as shown in Table 2.

Ranking by Grey Relational Analysis

The Grey relational analysis in the Grey theory (Deng, 1982) established a complete and accurate evaluation model for ranking [10].

Grey Relational Generating

When the units in which performance is measured are different for different attributes, the influence of some attributes may be neglected. Therefore, processing all performance values for every alternative into comparability sequence, in a process analogous to normalization, is necessary. This processing is called grey relational generating in GRA [10]. The measurement value for each evaluation criteria is shown in Table 3.

For MADM problem, the ith alternative can be expressed as A = (y , y , y ,…,y ,… y ) where is i i1 i2 i3 ij imthe performance value of attribute j of alternative i. The term y can be translated into the comparability i sequence X = (x , x , x ,… x ,… x ) by equations (1) i i1 i2 i3 ij im

yij

Table 2 Weightage of parameters

Parameters WeightR 36A 23S 17T 13C 11

Table 1 Pair-wise comparison matrix

R A S T CR 1 1 ½ 2 4 3A 2/3 1 2 1 2S ½ ½ 1 2 2T ¼ 1 ½ 1 1C 0.3333 0.5 0.5 1 1

SUM Col. 2.75 4.5 6 9 9





and (2).

(1)

(2)

Equation (1) is used for larger-the-better attributes and equation (2) for the smaller ¾ the better attributes. The rationalised values of the evaluation criteria is shown in Table 4.

Reference Sequence Definition

After the grey relational generating procedure, all the performance values are scaled into [0, 1]. An alternative will be the best choice if all of its performance values are closest to or equal to 1, however, such type of alternative may not exist[10].

Calculation of Grey Relational Coefficient

Grey relational coefficient is used for determining how close x and x . The larger the grey relational ij 0jcoefficient, the closer x and x are. The grey relational ij 0j coefficients can be calculated by equation (3).

(3)

where γ (x , x ) is the grey relational coefficient 0j ijbetween x and x , Δ = x -x , Δ =min {Δ , i = 1, ½½0j ij ij 0j ij min ij2… n; j = 1, 2… m}; and Δ max=max {Δ , i = 1, 2,…, n; j = ij1,2,..m}.

The distinguishing coefficient is , when є [0,1]. z zAfter grey relational generating, Δmax will be equal to 1 and Δ will be equal to 0. The computations of min

Grey relational coefficient is shown in Table 5 and the coordinally ranking of criteria is shown in Table 6.

Grey Relational Grade Calculation

After calculating the entire grey relational coefficient γ (x , x ), grey relational grade can be calculated using (4).

(X , X ) is the grey relational grade between X and X . 0 i 0 iThe highest grey relational grade with the reference sequence, it means that the comparability sequence is most similar to the reference sequence, and that alternative would be the best choice [10]. Different Grey relational grades are shown in Table 7.

Conclusions

This paper tries to propose an evaluation method to determine the overall performance for each RP method. The optimum decision can then be made based on the overall performance. Moreover, from the equations and a numeric example for method selection, this study obtains the following advantages:

1. It is very convenient to perform overall measurement based on each component's requirements. The overall performance can determine the order for selecting the suitable RP method.

0j ij

Table 3 Measurement value for each evaluation criteria

R A S T CSLA 4 0.129 62 240 5500SLS 12 0.205 43 240 58003DP 18 0.319 14 180 2000FDM 28 0.289 22 300 3200

Table 4 Data rationalizing

R A S T CSLA 1 1 1 0.5 0.07894SLS 0.66667 0.6 0.6041 0.5 03DP 0 0 0 1 1FDM 0.41666 0.15789 0.1666 0 0.6842

Table 5 Grey relational coefficient

R A S T CSLA 1 1 1 0.6666 0.5205SLS 0.75 0.71428 0.7164 0.66666 0.53DP 0.5 0.5 0.5 1 1FDM 0.6315 0.54285 0.5454 0.5 0.76

Table 6 Grey relational grades and ranking

GRA Grades RankingSLA 0.770164 1SLS 0.746667 23DP 0.713171 3FDM 0.5 4

Table 7 Grey relational grade

R A S T CSLA 0.8 0.77777 0.77907 0.75 0.6666SLS 0.6666 0.66666 0.66666 1 13DP 0.7307 0.68627 0.6875 0.6666 0.80645FDM 0.5 0.5 0.5 0.5 0.5

2. The enterprise can choose its own appropriate goal and weighting value for each evaluation factor based on the characteristic demand of the component in order to select the most suitable component.

Figure 1 shows that the considered parameters in the various RP methods are performing better when they are closer to the outer side of the radar and poor performing or undesirable parameters are near to the zero point or closer to it. For any change in the obtained values the parameter must need to be optimize or improved.

References

1. M N Islam, B Boswell, A Pramanik. An Investigation of Dimensional Accuracy of Parts produced by Three Dimensional Printing, Proceedings of the World Congress on Engineering, WCE 2013, London, UK, I, July 3 - 5, 2013

2. A M Romouzy-Ali, S Noroozi, P Sewell, T Humphries-Smith. Adopting Rapid Prototyping Technology within Small and Medium-sized

Enterprises: The Differences between Reality and Expectation, International Journal of Innovation, Management and Technology, 3(4), August 2012

3. S H Masood, M Al-alawi. The IRIS Rapid Prototyping System Selector for Educational and Manufacturing Users, Int. J. Engng Ed., 18(1), 66-77, 2002

4. V Shende, P Kulkarni. Decision Support System for Rapid Prototyping Process Selection, International Journal of Scientific and Research Publications, ISSN 2250-3153, 4(1), January 2014.

5. H S Byun, K H Lee. A Decision Support System for the Selection of the RP Process using the Modified TOPSIS Method, Int. J. Adv. Manuf Technol, DOI 10.1007/s00170-004-2009-2,26, 1338-1347, 2005.

6. M Shahrabi, M Javadi. Selection of Rapid Prototyping Process using Combined AHP and TOPSIS Methodology, International Journal of Information Science and System, ISSN 2168-5754, 3(1), 15-22,2014.

7. B N Panda, B B Biswal, B B L V Deepak. Integrated AHP and Fuzzy TOPSIS Approach for the Selection of a Rapid Prototyping Process underMulti-Criteria Perspective, Department of Industrial Design, NIT Rourkela, 2013.

8. F Peres, C Martin. Design Methods Applied. to the Selection of a Rapid Prototyping Resource, Rapid Prototyping Center, Laboratoire Productique Logistique Ecole Centrale de Paris, Grande Voie des Vignes 92295 Châtenay-Malabrycedex FRANCE,2010.

9. C-H Tsai, C-L Chang, L Chen. Applying Grey Relational Analysis to the Vendor Evaluation Model, International Journal of The Computer, The Internet and Management, 11(3), 45 – 53, 2003.

10. T L Saaty. Decision Making with the Analytic Hierarchy Process. Int. J. Services Sciences, 1(1), 2008.

Figure 1 Graphical model of grey relational coefficient



Futuristic Manufacturing for Equitable Development of India: Significance of Sustainable ManufacturingP K Phukan Contracts and ProcurementBrahmaputra Cracker and Polymer Limited (Central Public Sector), Lepetkata, Dibrugarh District, Assam. e-mail: [email protected]

Abstract

What is produced today should be manufactured by sustainable manufacturing process. It should not impact our future generation. Manufacturing remains critically important to both the developing and the advanced world. In the former, it continues to provide a pathway from subsistence agriculture to rising incomes and living standards. In the latter, it remains a vital source of innovation and competitiveness, making outsized contributions to research and development, exports, and productivity growth. But the manufacturing sector has changed — bringing both opportunities and challenges. The new era of manufacturing will be marked by highly agile, networked enterprises that use information and analytics as skillfully as they employ talent and machinery to deliver products and services to diverse global markets. As long as companies and countries understand the evolving nature of manufacturing and act on the powerful trends shaping the global competitive environment, they can thrive in this promising future. Reduction in energy consumption with respect to machine shops; capacity enhancement through manufacturing system redesign; weld shop productivity improvement through elimination of process, parts, quality and equipment downtime; alternative cooling techniques and reducing emissions, are routes to sustainable manufacturing. For manufacturer; sustainability has been emerging as a new competitive requirement to achieve differentiation in market. The current proposed work is based on development of sustainable manufacturing model for Indian manufacturing and proposed a framework for improving the performance to make them more sustainable.

Keywords : Manufacturing; Sustainability; Environment; Consumption; Competition

Introduction

Sustainability is an increasingly important requirement for human activity, making sustainable development a key objective in human development. At its core, sustainable development is the view that social, economic and environmental concerns should be addressed simultaneously and holistically in the development process.

Sustainability has been applied to many fields, including engineering, manufacturing and design. Manufacturers are becoming increasingly concerned about the issue of sustainability. For instance, recognit ion of the relat ionship between manufacturing operations and the natural environment has become an important factor in the decision making among industrial societies.

‘With the global focus shifting to India’s ‘Make in India’ initiative, a surge in demand for goods is expected in the future. Manufacturing decisions

should not be arrived at without considering long-term sustainability, according to the President, Indian Machine Tool Manufacturers’ Association (IMTMA). To maintain a sustained national GDP growth of 9-10 % per annum, it is essential that the manufacturing sector in India also grows steadily at 14-15 % per annum over the next three decades. To achieve this, India needs to rapidly enhance its competitiveness in manufacturing by attracting global investors through the creation of world-class infrastructure.

As economies mature, manufacturing becomes more important for other attributes, such as its ability to drive productivity growth, innovation, and trade. Manufacturing also plays a critical role in tackling societal challenges, such as reducing energy and resource consumption and limiting greenhouse gas emissions. Making manufacturing sustainable requires balancing and integrating economic and environmental societal objectives, supportive



policies and practices. Appropriate trade-offs are often necessary, considering the diverse interests of manufacturers and society. Furthermore, relevant, meaningful, consistent and robust information on sustainable manufacturing must be available and utilized by organizations and their managers if sustainability is to improve in manufacturing. An exciting new era of global manufacturing is ahead — driven by shifts in demand and by innovations in materials, processes, information technology, and operations. The prospect is for a more global’ manufacturing industry, in which developing economies are the source of new customers as well as the source of low-cost production. It can also be a time of rapid innovation, based on new technologies and methods.

This article describes sustainable manufacturing as a tool for futuristic manufacturing which includes consideration of green manufacturing, life cycle factors, and priorities in advancing manufacturing operations and processes. A case study is presented in which sustainability is considered holistically in decision making for a manufacturing operation. The objective is to improve understanding and to foster advances in sustainable manufacturing. This objective is particularly important since increased research, information, and technology transfer is needed if sustainable manufacturing is to become adopted quickly and in a widespread manner in the future.

Background: Sustainability and Sustainable Consumption and Production

In order to describe, understand and apply sustainable manufacturing, it is essential to have knowledge of sustainability and Sustainable consumption and Production. These topics are explained as follows.

Sustainability is a concept that has been defined in many ways and has different meanings to different people. Sustainable development was introduced in a widespread way by the Brundtland Commission, which defined it as development that ‘meets the needs of the present without compromising the ability of future generations to meet their own needs’ [1].

The 2005 World Summit on Social Development identified sustainable development goals, such as economic development, social development and environmental protection. Sustainable development consists of balancing local and global efforts to meet basic human needs without destroying or degrading the natural environment. The simple definition that sustainability is something that improves the quality

of human life while living within the carrying capacity of supporting eco-systems though vague, conveys the idea of sustainability having quantifiable limits. While the United Nations Millennium Declaration identified principles and treaties on sustainable development, including economic d e v e l o p m e n t , s o c i a l d e v e l o p m e n t a n d environmental protection it continued using three domains: economics, environment and social sustainability. More recently, using a systematic domain model that responds to the debates over the last decade, the circles of sustainability approach (Figure 1) distinguished four domains of economic, ecological, political and cultural sustainability. This is in accord with the United Nations Agenda 21, which specifies culture as the fourth domain of sustainable development.

At its core, sustainability is simply the ability to endure or survive, which has significant ramifications. For instance, sustainability describes the productivity and diversity over time of biological systems, from an ecological perspective, and the potential for long-term welfare, from a human perspective. The latter depends on the wellbeing of the natural world, including the responsible use of natural resources and disposal of wastes. Sustainability involves stabilizing the currently disruptive relationship between humanity and our planet [2]. Such an effort is challenging, as the human system and the planetary system are both very complex.

In the context of human development and environmental stewardship, the term sustainability has ideological, political, ecological and economic



Figure 1 Circles of sustainability

contexts [3] and, in this framework, it is most commonly seen as a derivation of the term sustainable development [4]. Sustainability can be viewed as having three parts: environmental, economic and social (including political).

As a consequence, achieving sustainability requires an integrated approach and multi-dimensional indicators that link a community's economy, environment and society.

Sustainable consumption and production (SCP) means production and consumption to satisfy human needs with minimal impact on the environment. The principle was first proposed in Rio De Janerio Summit, 1992 and later recognized in World Summit on Sustainable Development and the Marrakech process led by UNEP and UN DESA. On demand side, SCP aims at creating a balance between demand needs and the technology adopted to fulfill it. Sustainability is ecological in disposition, which basically means in order to preserve the resources, more focus need to be paid on safer, greener and clean technology. This forms the keystone of all global environmental conventions and protocols. Sustainable consumption and production (SCP) is about ‘the use of services and related products, which respond to basic needs and bring a better quality of life while minimizing the use of natural resources and toxic materials as well as the emissions of waste and pollutants over the life cycle of the service or product so as not to jeopardize the needs of further generations (Oslo symposium, 1994)’.

SCP aims at ‘doing more and better with less’, increasing net welfare gains from economic activities by reducing resource use, degradation and pollution along the whole lifecycle, while increasing quality of life. This change towards SCP involves different stakeholders, including business, consumers, policy makers, researchers, scientists, retailers, media, and development cooperation agencies, among others. It requires a systemic approach and cooperation among actors operating in the supply chain, from producer to final consumer. It involves engaging consumers through awareness-raising and education on sustainable consumption and lifestyles, providing consumers with adequate information through standards and labels and engaging in sustainable public procurement, among others. The schematic diagram of SCP is shown in Figure 2.

One of SCP’s main goals is to ‘decouple’ economic growth and environmental degradation by increasing the efficiency of resource use in the production, distribution and use of products, aiming

to keep the energy, material and pollution intensity of all production and consumption functions within the carrying capacities of natural ecosystems. SCP requires ‘lifecycle thinking’ to increase the sustainable management of resources and achieve resource efficiency along both production and consumption phases. With this lifecycle approach, SCP goals and actions Become powerful levers to accelerate the transition to an eco-efficient economy and turn environmental and social challenges into business and employment opportunities, while decoupling economic growth from environmental degradation and preventing a rebound effect.

Sustainable Manufacturing

As per United Nations’ sustainable manufacturing is defined as:

Sustainable manufacturing ‘meets the needs of the present without compromising the ability of future generations to meet their own needs’. Sustainable manufacturing is defined as the creation of manufacturing products that use processes that minimize negative environmental impacts, conserve energy and natural resources, are safe for employees, communities, and consumers and are economically sound. The overall goal of sustainable manufacturing is to obtain a view of the whole product cycle and optimize the life cycle of the manufacturing systems, products and associated services. With this view, manufacturers can not only produce more sustainable products but their manufacturing processes will become more sustainable, which increases the company’s total economic, social, and environmental benefits (Figure 3).



Figure 2 Concepts of SCP

The link between manufacturing and its operations to the natural environment is gradually becoming recognized. Progress, profitability, productivity and environmental stewardship are now seen as needing consideration by manufacturing organizations [5]. Improving environmental stewardship and sustainability, while maintaining profitability and productivity, are increasingly viewed as strategic goals of manufacturing companies.

Manufacturing and the Environment

Sustainable manufacturing seeks to produce goods profitably while minimizing a firm's environmental impact, natural resource use, and energy consumption. Evidence shows that companies that use both environmentally and economically sound manufacturing practices can gain significant competitive advantages.

The environment is the source of materials and energy for manufacturing, as well as the limiting factor. While humans have invented and created extraordinary compounds and technologies, at source, they all come from constituents found in natural environment. It is stated that the planet is a closed system, where neither the sun’s power get saved during entry nor exit in any appreciable quantities. Rather, the environment is a factor in each part of the manufacturing process: siting a plant; sourcing materials; ensuring energy; distributing materials and products; managing emissions and waste; meeting consumers’ desires, and providing a habitable planet. Environmental considerations should be included in all stages of manufacturing life

cycle to assess and manage potential risks. The inputs to and outputs from each stage of manufacturing life cycle should be analyzed to assess their impact on the environment. From the industry angle emphasis should be placed on different stages of manufacturing and product life cycle as shown in Figure 4.

Traditionally, strategies for manufacturing have considered production process comparisons for the volume/variety matrix of the products [6]. Today, manufacturing strategies generally account for products and processes, as well as other parameters like practices, so as to incorporate organizational and philosophical elements of manufacturing strategy.

Environmental factors for a company or an industry refer to variables and conditions around that company and industry that affect its working and performance, but which cannot be controlled. Manufacturing operations and the natural environment are becoming increasingly linked. To incorporate a measure of environmental impact in manufacturing strategies, expressions for assessing the environmental impact (EI) on society can be used. One common expression for the environmental impact on society is EI = P × A × T, where P, A and T denote population, affluence and technology respectively [7–9]. Population is difficult to constrain and affluence is increasingly sought by people. Thus, technology, which can be defined as the knowledge of an organization [10], is the factor that can be improved to reduce environmental impact.



Figure 3 Different components of sustainable manufactureing

Figure 4 Stages of manufacturing and corresponding impact on environment

The technology category relating to the environment and manufacturing is affected by the following three factors:

Product: The manufacturing strategy for environmentally benign products often involves a design process which accounts for environmental impacts over the life of the product. Consequently it is normally associated with the use of design for environment (DFE) and life cycle analysis (LCA) methods [11] . Designing products to be environmentally benign can contribute to their successful introduction and maintenance. Product flexibility, for example, allows for environmental improvements, like materials substitution, while retaining competitiveness. The expected decrease in product life cycles with increased product customization is likely to make flexibility increasingly important.

Process: Environmental improvements related to manufacturing processes are linked to reduction, reuse, recycling and remanufacturing. Zero-emission (that is, closed-loop) manufacturing views the manufacturing system as an industrial ecosystem, and requires the reuse of wastes or by-products within the manufacturing system. Thus, zero-emission manufacturing requires capabilities for pollution prevention (for example, substitution) and waste reuse. Flexible manufacturing also requires the capability for material flexibility, and manufacturing equipment that can accommodate variations in material flows can assist in enhancing sustainability while maintaining competitiveness. For instance, more efficient and recyclable packaging designs can make packaging more sustainable.

Practice: An important environmentally-based influence on organizational manufacturing practices is ISO 14000 certification which can support organizational practices but does not make environmental improvements a certainty on its own [5]. Practices can be used strategically to improve manufacturing, through such other activities as benchmarking and performance measurement, since such schemes assist managers in developing and maintaining new environmental programs and technology.

These three factors overlap in some areas and are interdependent and synergistic.

Among the various environmental aspects, energy is the strongest focus area for most Indian manufacturers. This is because a reduction in energy consumption also correspondingly reduces the cost of manufacturing. Companies are driving

improvement in this area through two approaches-the first is replacing existing equipment with energy-efficient alternatives, and the second is productivity improvement on the shop floor, to rece the energy consumed for the manufacture of each unit.

In a manufacturing setup, the supply chain has a significant impact on the environment. Logistics contribute significantly to the emissions generated by manufacturers, while suppliers, in addition o emitting Greenhouse Gases (GHG), also contribute to waste generation, effluents and natural resource consumption. And so, merely adopting green manufacturing practices inside the boundary walls of the factory may not reduce the desired level of environmental impact; instead, it becomes imperative to also include the supply chain in the scope, in order to bring in the required improvements.

There are three main stages at which the organization can bring in a stronger focus on environmental consciousness.

�Product and process design stage.

�Equipment procurement/technology change stage.

�Manufacturing stage.

Using sustainability indicators as a performance indicator further strengthens employee involvement in improvement initiatives that are targeted at conserving and preserving the environment. Sustainability reporting could be another tool that companies can adopt to further strengthen their commitment to sustainability.

Manufacturing decision makers normally addressed only the economic aspect of sutainability in the past, whereas corporations recently have started to address environmental sustainability. Such tools are becoming increasingly common and include carbon footprint estimation, life cycle assessment [12–15] and life cycle management, design for the environment, and product stewardship.

Manufacturing and Sustainability

Sustainable manufacturing evolved from the concept of sustainable development, which was coined in the 1980s to address concerns about environmental impact, economic development, globalization, inequities and other factors. Sustainable production was introduced at the 1992 UNCED conference in Rio de Janeiro as a guide to help companies and governments transition towards sustainable development. Research into these are is ongoing by many. Several definitions exist for sustainable manufacturing and production. For instance,



sustainable manufacturing is defined by the US Department of Commerce defines as he creation of manufactured products that use processes that minimize negative environmental impacts, conserve energy and natural resources, are safe for employees, communities, and consumers and are economically sound, while the Lowell Center for Sustainable Production defines sustainable production as he creation of goods and services using processes and systems that are Non-polluting, conserving of energy and natural resources, economically viable, safe and healthful for workers, communities, and consumers, socially and creatively rewarding for all working people.

There are two main facets to the concept of sustainable manufacturing. The first relates to he engineering involved in making a product and getting it to market, for example, the kind and amount of material inputs that go into it, and the resource cost required to make it and transport it for sale. Product and process design engineers work toward sustainability in this field by looking for ways to increase resource efficiency, and minimize waste and environmental impacts. The ultimate objective might be described as ‘net zero’ manufacturing, in which the resources expended in making the product are 100% recaptured, recycled, or replaced. The second facet of sustainable manufacturing is more holistic, and focuses on the effects of manufacturing – economic, social, and environmental – on workers, communities, consumers, and the world. Are factory workers safe? Are they paid adequately for their labor? How is the environmental health of communities affected by factories? What is the factory’s contribution to climate change? What is the proper role of a factory or company as an entity in the world?

Manufacturing industries nevertheless have the potential to become a driving force for the creation of a sustainable society. They can design and implement integrated sustainable practices and develop products and services that contribute to better environmental performance. This requires a shift in the perception and understanding of industrial production and the adoption of a more holistic approach to conducting business (Maxwell et al., 2006).

Sustainability has been interpreted in many ways, considering various requirements for many applications and different objectives. For manufacturing applications, the definition of sustainability requires refinement. Companies have developed and applied numerous approaches for

integrating sustainability into industrial operations, including people planet profits, sustainable management, ecological sustainability, and the ‘triple bottom line’ method. The latter method is describe by Elkington as a business case for sustainability, which involves a holistic approach relying on the principles of economic prosperity, environmental stewardship and corporate responsibility.

The adoption of more integrated and systematic methods to improve sustainability performance has laid the foundation for new business models or modes of provision which can potentially lead to significant environmental benefits. Efforts to create closed-loop, circular production systems have particularly focused on vitalizing disposed products into new resources for production, for example by establishing eco-industrial parks where economic and environmental synergies between traditionally unrelated industrial producers can be harnessed.

While more integrated sustainable manufacturing initiatives such as closed-loop production can p o t e n t i a l ly y i e l d h i g h e r e nv i r o n m e n t a l improvements in the medium to long term, they can only be realized through a combination of a wider range of innovation targets and mechanisms and therefore cover a larger area of Figure 5 For instance, an eco-industrial park cannot be successfully established simply by locating manufacturing plants in the same space in the absence of technologies or procedures for exchanging resources. In fact, process modification, product design, and alternative business models and the creation of new procedures and organizational arrangements need to go hand in hand to leverage the economic and environmental benefits of such initiatives. This implies that as sustainable manufacturing initiatives advance, the nature of the eco-innovation process becomes increasingly complex and more difficult to co-ordinate.

.



Figure 5 Close-loop production

Many aspects of sustainability in the context of manufacturing have been investigated, particularly in recent ears. For instance modeling and o p t i m i z a t i o n c h a l l e n g e s t o s u s t a i n a b l e manufacturing have been examined by Jayal et al, considering the product, process and system levels. A framework for sustainable production has been proposed by Nasr et al, who also provide a strategic approach to remanufacturing, which the authors identify as a key enabler to sustainable production. Approaches and methodologies for design sustainable supply chains and an evaluation of their performance have been described by Shuaib et al, as have novel approaches to reverse logistics and closed loop supply chains.

The evolution of the sustainability of manufacturing anticipated by the authors is described in Table 1. Traditional uses for manufacturing were developed without a focus on sustainability. Investments in plants and corresponding improvement and optimization efforts have typically been driven by increased productivity, reduced operating costs and work effort, and enforced regulatory compliance. Business decisions can increase the utilization efficiency of energy, materials, human and information resources as well as related technology and equipment. Future manufacturing systems are likely to be based on strategies that seek to optimize the capability to meet immediate facility needs in a way that enhances the environmental quality of future generations and the business prospects for the company in the future. The energy systems for

manufacturing facilities have advanced to improve operating cost structures, including load curtailment and shedding, and energy monitoring, as well as control of generators, HVAC systems, and thermal plants. The anticipated approaches in Table 2 can help meet the goals of sustainability.

Only those manufacturing companies that have the capability to operate in an environmentally sustainable way would survive. It means embarking on systems and processes which minimize the use of resources to produce more outputs. In layman terms, this is principled around zero waste and zero defects management. In the past, the Automation industry has concentrated on production line productivity and manufacturing costs reduction as key performance indicators. But, now it is increasingly applied to reduce scrap, eliminate defects and to minimize resource consumption.

The successful implementation of sustainability into manufacturing organizations is dependent on many factors. That includes,

Information: The quantitative and qualitative information required to make assessments is needed, for example, the quantity and type of metal a process uses, the quantity and type of pollutants emitted. However, such information is not always readily available and can be sometimes be difficult if not impossible to acquire.

Management and Culture: Sustainability issues, for example, environmental stewardship efforts, tend to

Table 1 Model for potential for implementing sustainability in manufacturing

Development Phase Potential for Modification Time before Commercial Cost Benefit of Manufacturing Proper Decision

Research Low-medium Long LowDevelopment Medium-high Medium MediumCommercialization Low-medium Short High

Table 2 Possible future evolution of the sustainability of manufacturing.

Present FutureRequired environmental compliance Enhanced environmental compliance often exceeding

minimal requirementsEconomic operational efficiency Increased operational efficiency beyond that

necessitated based solely on traditional economicsCommunication that supports business Communication to support expanded businessObjectives (reputation, brand recognition, etc.) objectives (reputation, brand recognition, corporate

social Responsibility, etc.)Meet legal regulations for compliance, with Shift from simply meeting legal regulations for little voluntary activity compliance to more voluntary activity, driven partly by

market forces for sustainability objectives





be dealt with in specialized departments rather than holistically by management. This can lead to inconsistent application and tends to discourage the development of a sustainability-oriented culture in the organization.

Procedures: Decision makers and staff are often not provided with the methodologies and procedures needed to ensure an organization's sustainability objectives and strategies are applied effectively, efficiently, consistently and robustly. One reason for this problem is that the number of variables to be taken into account in decision-making is usually very large. Employees need to take sustainability issues into account effectively in decision making and actions if sustainability objectives are to be achieved.

Models for Manufacturing and Improved Sustainability

Various models have been developed for implementing sustainability in manufacturing by improving the sustainability of manufacturing. Recently, frameworks for sustainable manufacturing, production and supply chains have been put forth, and modeling and optimization tools have been developed. Harland et al. propose an environmental health and safety technology engagement model (Table 1) that illustrates the potential for implementing sustainability objectives during the development of a product or process. This model includes three phases: research, development and commercialization. A significant time period, often lasting years, is normally involved in designing a new manufacturing product or process, and Table 1 shows the potential for implementing sustainability objectives differs with the time and phase of development. Manufacturing engineers and designers need to recognize this dependence to integrate sustainability effectively into processes or products.

Rather than considering the environmental factors only at one point in the product or process development cycle, a long-term commitment over the entire design process, from early research to process development, is usually more effective for integrating sustainability into manufacturing. Sustainability can be addressed in each of the three phases of the model:

Research: The first significant opportunity to influence the design process for sustainability is during the research phase at the pre-competitive level. At this phase, specific sustainability requirements and not-yet regulated concerns can be evaluated and examined, for example, energy and

resource use, pollution and climate change impacts. Early evaluation helps to ensure appropriate attention to sustainability at a time when it can be affected greatly, for example, research can focus on solving manufacturing environmental issues.

Development: During the development phase, effort to improve environmental performance is focused on system design and equipment selection using appropriate methods tools and methods, for example, design for environment, environmental footprint assessment, and life cycle analysis. Collaboration with vendors helps promote environmental improvements. The potential for modifications that enhance sustainability characteristics is high during this phase.

Commercialization: The efforts introduced during the development phase are extended and refined during commercialization activities, and involve cooperation with suppliers, vendors and customers.

The semiconductor equipment company Intel is an example of a company that strives to build sustainability into its products and processes prior to commercialization. Intel operates under a two-year model for new product development, alternating between silicon manufacturing technology one year and microprocessor architecture the next. This model introduces a new manufacturing process technology in the first year, allowing, for instance, reductions in semiconductor size and the subsequent manufacture of more semiconductors on a single wafer or placement of more transistors in an equivalent space. In the second year, this model introduces a new chip architecture or design with the same manufacturing technology. Each step provides the opportunity to establish objectives and strategies to reduce environmental impact, and Intel has worked with suppliers of semiconductor manufacturing equipment and materials to improve the environmental performance of various technologies using this approach.

Needs to Enhance Manufacturing Sustainability

The present examination highlights the importance of integrating sustainability, design for environment, life cycle assessment and other tools with manufacturing and relevant decision making structures. Several specific needs exist to enhance further manufacturing sustainability.

Approach: A more comprehensive, broad and integrated approach is needed for sustainability, which encompasses economic, social, environmental and other relevant considerations. An approach that

goes beyond individual companies can make the manufacturing industry more sustainable.

Methods and Tools: Enhanced methods and tools for manufacturing are needed to foster and support sustainability.

Data: More detailed, comprehensive and robust data are needed to support environmental impact and sustainability assessments, and measures across the overall product life cycle. Such data needs to be standardized where feasible.

Manufacturing Company Practices: Manufacturing companies should incorporate sustainability into their practices holistically. Practices that would be helpful include: improved measuring and monitoring of sustainability indicators by companies, company policies and governance that focus on sustainability, improved efforts to control a company's environmental impact, establishing a sustainability-supportive company culture and working conditions, enhancing awareness of sustainability among suppliers and customers, responding to their requirements and measures, and engaging the community to promote sustainability.

Government Policies: Governments and relevant agencies need to incorporate into policies, programs and operations stronger consideration of sustainability, environmental factors, and clean processes. This requires cooperation between internal and external partners.

Research: Significant collaborative research is needed in industry and academia in the fields of sustainability, manufacturing, design and environmental impact.

Importance of Manufacturing Sustainability

The importance of adopting sustainable manufacturing measures and strategies by companies are numerous and are becoming increasingly recognized. For instance, climate change is increasingly seen as caused by anthropomorphic activities and potentially having very serious consequences, while resources (for example, energy, materials, water) are now seen as subject to scarcities and in many cases non-renewability that can affect operations. Also, the global economic crisis of the last several years has raised questions about the viability and ultimately sustainability of existing business practices that aim for economic growth, but pay little attention to mitigating the negative impacts beyond the company. As a consequence, pressures for sustainable manufacturing have become increasingly put forward by many stakeholders, for

example, employees, investors, suppliers, customers, competitors, communities, governments, regulatory bodies.

Case Study

Industries are predominantly of Micro, Small and Medium enterprises, having little experiences in environmental issues as most of business is family owned business and being run by single owners. In addition to eliminate the wastes, there is need for fundamental shift in business model. The business that first makes the changes will have competitive advantages.

It is estimated that there are 311 lakhs MSME’s are

working India and in terms of value the MSME sector account 45% manufacturing output and 40% of total export of country. MSME’s contributes around 8.2% of GDP. In all the MSME’s approximate 732 lakhs people are employed. Out of total registered MSME, approximate 94.9% are Micro industry, 4.8% are small and 0.2% are medium enterprises. 67% industries are manufacturing industry. 90% of the MSME is propriety firms and being run by a single owner. The focus in proposed research will be manufacturing sector as it contributes in maximum.

MSME’s must focus on ‘trade-off zone’ where environmental benefits are weighed judiciously against value destruction. Only focus on value rather than compliance, emission or quarterly cost can provide entrepreneurs with information to set priorities and develop business responses. Entrepreneurs must set clear priorities based on potential impact on shareholder values. Within this frame work, environmental issues can be broken in three broad categories: Strategic, Operational and Technical.

Achieving sustainability will require stabilizing or reducing the environmental burden. That can be done by lowering the population, lowering the consumption or changing the technology to create wealth. Controlling the population is beyond feasibility at this stage and controlling the consumption will even worsen the situation. That leaves only the third option, that is, changing in technology to create wealth for them and society

both. MSME’s need to have clear vision at this stage to

guide them through three stages for environmental strategy:

Stage One: Pollution Prevention

This stage is governed by principal ‘prevention is better than cure’. Pollution control means cleaning up



waste after it has been generated. Pollution prevention focuses on minimizing or eliminates the waste before it created. MSME's need to build the prevention in manufacturing model at the stage of inception.

Stage Two – Product Stewardship

Product stewardship focuses on minimizing not only the pollution from manufacturing but also all environmental impact associated with full of life cycle of a products. The organization’s need to look for Design for Environment (DFE), a tool for creating products that are easier to recover, reuse, or recycle is becoming increasingly important. Cradle to crave analysis begins and ends outside the boundaries of company’s operation. By reducing material and energy consumption, DFE can be highly profitable.

Stage Three – Clean Technology

MSME’s with their eyes on future can begin to plan for and invest in tomorrow's technologies. The simple fact is that existing technology base in many industries is not environmentally sustainable. Cleaner technologies are desperately needed in Micro Small and Medium Enterprises.

Benefit of Sustainable Manufacturing for MSME's

Process Benefits

Material saving resulting from more substitution, reuse or recycling of production inputs.

®Better utilization of by-products, conversion of waste into valuable forms.

®Lower energy consumption during production process.

®Reduce material storage and handling cost.®Elimination of cost of activities involved in

discharge or waste handling, transportation and disposal.

Product Benefits

®Higher quality, more consistent products and lower products cost (material substitution).

®Lower packaging cost, more efficient use of resources by products.

®Lower net cost of products disposal to customer.®Higher product resale and scrap value.

Conclusions

The importance of integrating sustainability with manufacturing and design is highlighted, along with the need to utilize appropriate tools, like design for environment and life cycle assessment. The new world of sustainable technologies and business

strategies is undoubtedly a challenging and exciting emerging reality for the manufacturing industries. Key drivers of compliance, community expectations, risks, costs and market competition will ensure that those who don't adapt will be left behind. The role that manufacturing will play in creating and shaping this world is significant and will require steadfast commitment and effective strategies that embrace the full extent of sustainable possibilities. A sustainable organization will take a broad perspective of sustainability that includes environmental, social and economic criteria and engages the entire stakeholder community. Organizations to become more sustainable, managers must address the different dimensions of sustainability at the strategic level, both during the strategic decision-making process and as part of the strategy content at the corporate, business and functional levels. Managers and scholars can use the framework which have been provided to assess the degree to which organizations have strategically addressed sustainabi l i ty and to identi fy opportunities for further improvement. Developing an organization that regards sustainability as a cornerstone for doing business requires a strategic approach that integrates economic, environmental and social considerations in all aspects of business. Along with competitiveness, profitability and productivity, environmental stewardship and sustainability are likely to prove increasingly important for manufacturing in the future and in setting the main priorities for advancing manufacturing operations and technologies. Future prospects for sustainable manufacturing are mixed, w i t h i m p r o v e m e n t s a n t i c i p a t e d d u e t o environmental pressures, while a focus on economics may dominate at the expense of sustainability due to the ongoing global financial crisis.

References and Notes

1. World Commission on Environment and Development (WCED). Our Common Future; Oxford University Press, Oxford, UK, New York, NY, USA, 1987.

2. P Hawken. Blessed Unrest: How the Largest Movement in the World Came into Being and Why No One Saw It Coming; Viking: New York, NY, USA, 2007.

3. K Pezzoli. Sustainable Development: A Transdisciplinary Overview of the Literature. J. Environ.Plan. Manag. 40, 549–574, 1997.

4. W Visser. Sustainability in the A to Z of Corporate Social Responsibility, W Visser, D Matten, M Pohl,



N 5. J Sarkis. Manufacturing's Role in Corporate

Environmental Sustainability: Concerns for the New Millennium. Int. J. Oper. Prod. Manag. 21, 666–686, 2001.

6. R Hayes, S C Wheelwright. The Dynamics of Product-process Life Cycles. Harv. Bus. Rev., 57, 127–136, 1979.

7. T E Graedel, B R Allenby. Industrial Ecology and Sustainable Engineering; Prentice Hall, Upper Saddle River, NJ, USA, 2010.

8. S L Hart. Beyond Greening: Strategies for a Sustainable World. Harv. Bus. Rev., 75, 66–76, 1997.

9. D D Johnson, R Srivastava. Design for Sustainability: Product Development Tools and Life Cycle Economics. Proceedings of the 39th Annual Meeting of the Decision Sciences

Tolhurst (eds); Wile, West Sussex, UK, 2007. Institute, Baltimore, MD, USA, 1711–1716, 22–25 November 2008.

10. T C MacAvoy. Technology Strategies Case Notes, Darden School of Management; University of Virginia: Charlottesville, VA, USA, 1990.

11. E Beaver. LCA and Total Cost Assessment. Environ. Prog., 19, 130–139, 2000.

12. D F Ciambrone. Environmental Life Cycle Analysis, Lewis Publishers, New York, NY, USA, 1997.

13. M A Curran. Life Cycle Assessment: An International Experience. Environ. Prog., 19, 65–71, 2000.

14. R P Vignes. Use Limited Life-cycle Analysis for Environmental Decision-making. Chem. Eng.Progr. , 97, 40–54, 2001.

15. A Bernard, S Tichkiewitch. Methods and Tools f o r E f f e c t i v e K n o w l e d g e L i f e - C y c l e -Management; Springer, Berlin, Germany, 2008.



Green Production Concept for Future C K RoyApeejay Institute of Technology, School of ManagementGreater Noida District, G B Nagar 201308 e-mail : [email protected]

Abstract

Green manufacturing aims at reducing the carbon-stock in the environment. This is only possible by adopting new product designs and the process redesign and for that total reengineering is needed. The carbon emission is co-related with the use of energy for production and this means that the production system has to be oriented towards green. That will help in carbon stock reduction. To achieve this the corporate must accept the green manufacturing as a challenge and subsequently invest in designing, research and development and innovation. Green production also saves cost and enhances profitability by utilising man, machine and material. It also has a social importance and green products should be a message to the society and users of the product. The public around us should be educated in this respect. The green production will help in saving this Earth by controlling and reducing the carbon stock and global warming. Incentives should be provided in the form of carbon-credit and added rewards for each concerned should be given. Corporate should opt for green audit to compare the green performance on year to year basis. The entire society must understand the importance of green production, green habits and its needs to save our Earth. Unless we follow it the growing population of the earth will face problem to live comfortably. Think what we are going to give to our future generations? Social cost benefit (SCB) of green production and green product can not be measured in terms of any amount of money.

Keywords : Green production; Carbon-stock; Ozone layer; Re-design; Environmental friendly; Small fraction; Depletion; Natural resources; Harmony

¾

Introduction

There is no single complete definition about’ green production’ but the general concept is that it refers to the environmentally preferred attributes of a production system. Here it is more important to search the concept of ‘GREEN’. The green is that activity of production that helps in reducing the ‘carbon-stock’ of the atmosphere or space, inhabitant are living under. The carbon stock is increasing day by day that results in to warming of space and this earth causing an impact on ozone-layer.

In any production system energy is used in some form or other. Presently, to generate any energy, mostly electricity or fuel is used termed as power or heat. By redesigning the process of manufacturing by replacing with modern efficient high speed machines or alternate cheaper source of making it energy can be saved. Even minimising idle time or reducing the use of materials by redesigning, production the energy can be saved.

Before 1980's or say during 20th century less thought was given to green production. From the end of 20th century, 1990 onwards the world started conveying environmental friendly messages relating to green products, green production system and

green habits ranging from home to industry. The trend of green products attained a status of niche market and this is only possible if one and all do not concentrate on green production system. The trend of green production was quite slow and did not cover even a small fraction of the total green production process needed. It was the beginning of twenty first century when the world woke up and sensed the importance of global warming that was also co-related to depletion in natural resources and started it with some acceleration. The term ‘green’ was put at main stream and the impact on the practices adopted by major production process of industries. Most of the business houses or stake holders concentrated on profit maximisation by hook or crook, forgetting the concept of green.

Another definition of green product says that ‘the green-products are those that has less impact on the environment or are less detrimental to human health than traditional equivalents’. Green-production might adopt re-cycling of components and that may lead to green product supply to the society. Since recycling consumes lesser energy because of the fact that it is not started from the origin of material and it becomes an intermediate stage of production. Take the example of steel scrap melting and re-rolling of





iron rods. Here instead of starting from iron-ore, they use scrap. In actual process the blast furnace melt steel and use the molten cast iron in liquid for in the steel melting section for further reduction of iron to make it mild steel, carbon steel or alloy steel. Mini steel plants use scrap with sponge iron using electric ark furnace or induction furnace to get billets and re-roll it. In this case due to elimination of process and re-cycling the cost of energy used comes down by 60%.also the total cost of production is lower. Due to lower use of energy, saving use of coke, means reducing the generation of carbon die oxide (CO ). 2

This helps in reducing the carbon-stock of the atmosphere or the space over our head. It will be meaningful to mention the term ‘corbon-stock’. corbon-stock is a globally accepted yard stick that is the measurement of carbon percentage present in the atmosphere around us. It is measured in terms of its presence per cubic meter of air and for the entire world this information provided. Based on the reduction of carbon die oxide (energy equivalence) carbon credit it provided to industries or services that has controlled carbon emission in the production system or product development process. This carbon-credit is an incentive for the green production or green habits. The green production is co-related to green products as product of one industrial unit is used by another unit or public and this energy efficient product is indirectly help full in lower energy consumption that leads to manufacturing in a more energy conservative manner. Lesser of efficient non bulky packaging also helps.

Green production system is better classified and that are those that meets the following objectives:

(I) it helps in protecting environment or helps in reducing carbon stock.

(ii) that helps in reduction of harmful ingredients with that of nature-friendly one.

(iii) manufacturing a chemical or other products that help in sources of pollution in water supply system that endangers health by contamination of water and air. Most chemical industries and even others that has higher dangerous refuses must treat them well before discharging to the nature or public. Artificial dyes or fragrance are cause of skin diseases. The production system must have harmony with the society.

Another definition of green production and green product which is technical in nature and is used based is:

'It is energy efficient, means consumes lower energy

per unit of production is environment friendly and

has lesser harm to the environment that means our society and the environment around us should not suffer. It relates to the production process that is efficient in saving the use of energy directly or indirectly’.

A better example is energy efficient Godrej EON brand air conditioner that saves about twenty five percent of energy more than even five star rated other air-conditioner. These products are being used as a house hold goods, in hotels and also in industries and the saving on account of energy shall be quite significant.

Another example is water harvesting and using it for production where ever needed will save energy in the system. Water harvesting reduces the cost of water or steam and it also helps in raising the water table level of the earth.

The world is moving towards ‘NANO’ technology that relates to revolution in technology by minimising the size or weight of the product using better material and better designs. Today revolution is re-designing of the products with nano concept by reducing weight and its fuel or power efficiency and that is the new concept. Designing a drone of pocket size is a latest example. Take the case of smart phones and Personal computers where the designs are fast changing in terms of its performance, size and weight. use of substitute materials that are cheaper and use lesser energy in its production are helping in lowering carbon stock. The most suited example is auto mobile industry where total tare weight are decreasing with higher performance features. Compare the weight of old ambassador or fiat car brands with that of today’s products. Several auto mobile industries are using polymer based PVC components that uses lesser energy than made of steel or other metals and due to its lower density it helps in weight reduction as well.

In the United State researches has been made that studied building materials and buildings used for living by human beings that may be school, offices, factory or home. They have studied on Indoor environmental quality (IEQ) rating for buildings and it was introduced in US some of the developed countries are also following it. To meet the challenges of IEQ the products better IEQ were introduced and rated by an independent third party. Later on the furnishing and indoor materials used for the interior decoration in the buildings were studied from the volume organic component (VOC). The impact of negative VOC rating has been negative on the health of those who live in there because it causes various diseases such as asthma, allergy. Pulmonary infection and other effects. VOC also results in other



complications by its exposure and may even affect hormones gene activation. The brain development and efficiency is also affected silently by long time exposure to VOCs due to harmful chemicals from living rooms and work places.

In the Unites State there is regulation for VOC contents. A small example is that the VOC contains in the wall paint should not exceed 250 g/l. Low VOC or no VOC products are preferred. This is an indicator that the industrial production and processing system should adopt technology and inputs that have acceptable range of VOC. This adoption shall help in building a better product brand for those who adopt it fully. The VOC radiates continuously and it flows from all directions and effects the external environment as well. It is a silent keeler, the effect of which is traced after long time. Mainly for person having lung infection and breathing problem it is most harmful..

Alternative research and development of products helps in creating green products. The current example is invention and production of CLF lamps for lighting and decoration. CLF bulbs save about 70% of power consumption. If we calculate @ one CLF lamp of 27 W that is equivalent to more than 100 W of GLS bulb per person in India that has 125 crores of population the saving will be equivalent to several thermal power plants. Similarly fuel efficient cars help in reducing emission of carbon and other chemicals in the air. Compressed natural gas (CNG) helps in lower emission than petrol and diesel. Even the concept of bio-fuel is more environment friendly.

Use of bamboo and cane for furnitures and other house hold goods encourages green production and it helps in saving the environment. It is a replacement of wood. Bamboos and cane are available every where ans special in Asia and they come under the category of grass and legally these are not wood. There is no legal restrictions. The products made from cane and bamboo are presently made by skilled local carpenters in a tradition way. It requires little energy. These are hand made and in case a research is conducted and the process is mechanised in terms of slitting, bending, straitening and assembly the product that is green product shall be accepted by the users. The government organisations and NGOs may take up the issue for calculating a sense of advantages in using green products. This step will save wood and deforestation.

Another small example is using re-fills in the existing products and use its container. A refill of a pen is lighter by 80% by weight and if used in the same body shall help in reducing use of plastic and its processing cost of melting fitting etc. Use of shellac based products in bangles and decorative pieces shall

reduce the consumption of power and fuel as shellac has a very lower melting point compared to glass and will have good acceptance from the people/users. This industry if mechanised and innovated shall enhance the quality of the product and its acceptability. The glass melted for making bangles consumes ten times more power and fuel compared to shellac and the proportionate saving would be linear in nature.

Due to increase in computing and IT communication within the office or out side using internet and intranet the world is going to be paper less. The practice of adopting paper less offices and books helps in saving paper. Since paper is usually made from wood pulp that consumes huge energy in its processing and manufacturing. No doubt it has reduced consumption of paper but allot more needs to be done. Similarly packaging is another area where R&D and innovation are needed. Packaging uses much material in its manufacturing process. In case these are made lighter there will be saving on power and fuel adding advantage to reduce carbon stock.

Proper maintenance of plant and machinery and good house keeping results in to lower energy consumption and also helps in increasing the overall productivity. Maintenance is no more an un noticed centre in a manufacturing activity. Today maintenance is being considered as a cost centre that adds to the profit of an industry. Most of the small scale and medium scale industries do not give much care and importance to maintenance and for them it is ‘repair of machine after the break down takes place’ and this means when the machine ceases to produce. Today maintenance is to add the Productivity, cost saving and energy saving as well. In a simpler way to understand it think of an old car that emits harmful excess outgoing flue in the air and due to higher consumption of fuel per km of the distance covered, it uses more fuel for the distance it covered by adopting proper maintenance. By adopting proper maintenance of the plant and machinery the productivity increases and the power and energy consumption per unit of production is reduced.

In maintenance of plant and machinery following steps need to be adopted:

(i) Proper and scientific maintenance planning needs to be adopted.

(ii) Total productivity maintenance (TPM) needs to be planned and adopted.

(iii) Reliability centred maintenance (RCM) needs to be adhered.

(iv) Proper spare part management is needed.



In the earlier days the maintenance activity was limited to repair of machinery after break down or stoppage of machine. Today maintenance has been termed as science and there is well organised maintenance department. The major maintenance functions are adopted by this department that has turned as a cost centre. The maintenance should be preventive and in time for which proper schedule is prepared. For running maintenance that is an easier job of repetitive nature like daily cleaning, oiling, voltage checking and belt adjustment etc. To handle the running maintenance operators of machine should be trained and prepared to reduce the burden of the main maintenance department. This will result in to time saving.

Achieving higher reliability in manufacturing and maintenance, operators help in reducing waste, rejection, and waiting time to help maximisation of machine efficiency. An excellent maintenance management allows us to get the most out of assets we have and this means the asset utilisation ratio is improved Redefining the role of maintenance management as part of the total reliability system provides the infrastructure, operational processes and staff, fully involved that results in to total improvement All these factors lead to energy saving by enhancing machine efficiency and enhanced productivity. Per unit cost of energy is reduced. Several SSI and SMEs that are closely held companies do not like to spend funds on maintenance because they care more for product out put. It is the right time that the top management is fully involved in decision making to strengthen the maintenance activity that helps in green production. They should understand the importance of saving energy that helps in carbon stock reduction. Though it is a hidden indirect approach but quit feasible and easier to adopt. The planned maintenance has an overall impact on ‘green production’.

Use of capacitors or voltage corrector reduces the power consumption. Most of the developing nations do not get proper quality of power with constant voltage supply. The use of capacitor or voltage corrector reduces the power consumption. Due to increase in the quality of power, and increase in power factor the energy is saved that has green impact on in totality.

Green manufacturing or green production needs application of R&D and innovation. Under this the design of the products is more important. Also the method of production and processing helps maximum in achieving the objectives of green production. It minimises the waste generation thus pollution that is achieved through product design,

standardisation and process planning. The world is going for ‘nano’ technology and product design is oriented accordingly. These designs are compact, lighter in weight, uses lesser materials. All this will result in to energy saving that may be fuel or power. It will help in reducing carbon emission thus helping in reducing the global 'carbon-stock' around us helping in reduction of global warming.

Green production also helps in enhancing the reputation of the corporate in the mind of stake holder, society and product users. Apart from cost people of developed countries when educated about green production and green products shall prefer to buy green products even at a higher price since the long term cost benefits and its social cost benefits shall satisfy them. A time will come when others will also follow it.

Green production audit should be adopted by each corporate to exactly understand the impact of green production on the society and the atmosphere. The cost or fund incurred and gains should be high lighted in the reporting/auditing. In future the corporate need to invest in product design, production process system for improvement rather than controlled technology. This will help in lesser use of power and fuel and scrap minimisation. There should be a separate budget for R&D, design, and new process selection. The budget earmarked shall help in freely adopting steps for green production system with out waiting for fund. Use of advanced technology helps in promoting green production strategy. For example, compare the process of manufacturing ambassador cars and that of maruty. The lack of R&D, New designs ousted Hindustan Motors from the marker.

Another area of importance is that for a new product develop an innovative production system that takes birth from an excellent R&D system adopted. Mahindra & Mahindra is the example that recruited one hundred and fifty engineers in advance for designing their two wheeler project.

To achieve an effective result following process or steps need to be followed:

<Substitute and renewable here renewable means which can be reversed in process and is friendly for nature. The examples are wind power, sun energy, bio-technology, use of water transportation, biological ¾ fuel for diesel needs to be stressed upon. Recycling is an other example of renewability. Example being re-cycling of PVC or steel scrap. Statement of Mr K Gopalakrishna is worth praising who state ‘if airlines use bio-fuel, I will not feel guilty

¾



travelling’ this was accepting the truth of the green fuel.

<Funding R&D facilities is necessary to design and develop new products that are green friendly.

<Educating the employees and workers who are the main performers and should be oriented in the area of energy saving and prevention of environment contamination. This will be an effort at root level. The process of green idea rewards should be installed in the organisation to encourage each and every one in the organisation starting from sweeper to GM.

<TQM to be followed by ISO rout that provides a documented system of working that helps in g re e n sys te m . I S O - 1 4 0 0 0 c ove r s t h e environment related processes. On the Japan's pattern a separate quality circle (QC) may be introduced where operators have an opportunity to give ideas.

<The world is trying to attain a zero emission level by controlling the manufacturing system keeping in mind the impact of environmental improvement. In actual practice zero level is not possible but it should be tried to reach a level very nearer to zero-level.

The entire world is concerned with green production to reduce or eliminate pollution of environment mainly due to emission of carbon. Unless it is done, this good Earth will not be available for our next generation to live on. Do not think of your present comfort during your life time but think about your grand sons and next generations to come. ‘Save this earth’ is the slogan that is only possible by adopting line of greener and more greener production that will control the pollution and improve the environment to make this earth liveable. The globes population is approaching about 800 crores and is bound to increase further. To keep it well more and more responsibilities lies on us. Adopting R&D, innovation and greener habits will only help in meeting the future challenges.

Conclusion

Green manufacturing aims at reducing the Carbon-Stock in the environment. This is only possible by adopting new product designs and the process redesign and for that total re-engineering is needed.

The carbon emission is correlated with the use of energy for production and this means our production system has to be oriented towards green. That will help in carbon stock reduction.

To achieve this the corporate must accept the green manufacturing as a challenge and it should be taken seriously at the top level of management. To achieve this corporate must budget and invest in designing, research and development and innovation.

Green production also saves cost and enhances profitability by utilising man, machine and material that are major inputs in a manufacturing system. It also has a social importance and green products should be a message to the society and users of the product. The public around us should be educated in this respect.

The green production will help in saving this Earth by controlling and reducing the carbon stock and warming. Incentives should be provided in the form of carbon-credit and added rewards for each concerned should be given.

Corporate should opt for green audit to compare the green performance on year to year basis. The entire society must understand the importance of green production, green habits and its needs to save the earth. Unless it is followed, the growing population of the earth will face problem to live comfortably. One should think what he is going to give to his future generations. Social cost benefit (SCB) of green-production and green product can not be measured in terms of any amount of money.

References

1. Fighting the Goods Fight at Northrop, Bergstorm, Robin Manufacturing Management on Giving New Thought to Other Thought Manufacturing Management, 103, November 1991.

2. F Richard. The Move to Environmentally C o n s c i o u s M a n u f a c t u r i n g , C a l i f o r n i a Management, 139, November, 1996.

3. Economic Times. Statement of M & M about R&D

¾ P S Ashok. Head, R&D Centre and A Mathur, President, Two Wheeler Division, May 22, 2012

4. OET. Statement of K Gopalakrishnan, Co Chairman, Infosys, ‘If airlines use bio-fuel. I will not feel as guilty travelling’, July 12, 2012

Lean, Agile and Le-agile ManufacturingT K Roy Irrigation Division, Gammon India Limited, Mumbai, Indiae-mail: [email protected]

Abstract

Lean manufacturing was devised and adopted by Taiichi Ohno and Massakai Imai at Toyota plant. It is known as Toyota production system (TPS). It works on the philosophy of reducing seven types of ‘wastages’ covered under; muda (non-value adding work), muri (overburden) and mura (unevenness of work-flow). This system reduces cost substantially and increases productivity and quality. This has been proved extremely successful in the cases of mass production.

Agile system is a later development, which keeps the production system alert for adopting quick changes in production line to produce a different variety of product. It advocates for undertaking production only on receipt of orders as against mass production in Lean system.

Le-Agile system is a hybrid of the above two production systems. In this, products are kept in semi-finished conditions applying Lean manufacturing. Agile system is adopted thereafter to finish as per demands of different variants.

Keywords : Lean; Muda; Muri; Mura; 5 ‘S’; JIT; KANBAN; PDCA; Bench marking; Six-sigma; Zero defect; FMEA; Poka yoke; Quality circle; Kaizen; PERT; CPM; Agile; Le-agile; Digitalizing operations; E-tailing.

Brief History

TAIICHI OHNO: 29 02 1912 – 28 05 1990

Lean manufacturing system was originated from Toyota, Japan. Toyota’s founder Sakichi Toyoda was in favour of bringing out the best in manufacturing. His son Kiichiro Toyoda together with Taiichi Ohno started their whole hearted journey in that direction from the year 1948. They gradually established a manufacturing system known as ‘Toyota production system’ (TPS) by 1975. The system thus embedded in TPS is popularly known as ‘lean manufacturing’. It may be noted that quite a good number of eminent scientists/engineers/personalities were involved basically in Japan, who professed various changes in the quality management system. These quality systems were welcomed by the war ravaged tiny country and they whole-heartedly implemented this. Toyota became a leader in implementing these and thus could produce marvellous results. The great persons who brought about this industrial revolution in Japan are;

Edward Deming (1900 – 1993), Philip Bayard Crosby (1926 – 2001)Josheph Juran (1904 – 2004)Genichi Taguchi (1924 – 2012)Kaoru Ishikawa (1915 – 1989)Shigeo Shingo (1909 – 1990)Taiichi Ohno (1912 – 1990)Massakai Imai (Born - 1930)

Lean Manufacturing Concept

It attempts to reduce seven types of wastages covered under:

r‘Muda’ or non-value adding works (for example; Transportation).

r‘Muri’ or overburden (for example, trying to extract work from man/machine beyond its capacity)

r‘Mura’ or unevenness of work (say, one work station taking longer time than the next one).

Muda is a Japanese word which means non-value addition. There are always some non-value adding works which are incidental to produce a product. The quanta of such works are necessarily to be reduced to the bare minimum and the cost thereof should be marginalised. The seven types of such wastes are;

Transportation: Each time a product is moved/ handled, it stands the risk of being damaged, lost, delayed, etc. By transporting raw materials/WIP/ finished goods, no transformation of product takes place. But this is essential. Hence, the transportation must be reduced to barest minimum and must be done in the most economical and safest way.

Inventory: Inventory, be it in the form of raw materials, work-in-progress (WIP), or finished goods, blocks capital without making any change to the product. In addition to additional cost aspect, the



long inventory is susceptible to wearing/ damage/ spoilage/ requiring refurbishing etc.

Motion: It indicates various types of movements by the workers/equipment/WIP, which also do not add any value. These, naturally need to be kept at the minimum level.

Waiting: In the traditional manufacturing process, the products spend considerable time waiting to be processed. This is another type of waste, which should be brought down to zero.

Over-processing: Over-processing refers to manufacturing of the items with much more precision than are required. Such wastes need to be arrested and kept within the specified levels only.

Over-production: Over-production occurs when production overshoots the market demand including logical inventory. This is too dangerous a situation and should be tackled properly.

Defects: Whenever defects occur, rejection/ rework/ passing on the defective item to the customer are involved. These incur more cost besides losing reputation. These need to be eliminated in totality.

Muri is also a Japanese word meaning overburden. It has been observed in the industry that sometimes the management pushes the worker or machine to do more work than it is logically possible. This is too dangerous and is bound to cause severe break-down in man/machinery. Non-congenial work place with dusts, gases, heat or other types of impediments are deterrents to good work culture/health/employee morale etc. These must be removed forthwith to get better results.

Mura too is a Japanese word which denotes unevenness. This unevenness may occur in various aspects like;

(i) There could be unevenness or variations in qualities of the products. This needs to be assured through proper process control.

(ii) There could be unevenness or variations in the process flow chocking some work places while causing idling at other places. Process flow should be studied carefully and must be standardised to maintain even flow.

(iii) Uneven distribution of workload among various work stations may also cause problems. Operations to be conducted in each work station need to be carefully designed so that all the work stations perform their work in unison to avoid time lapse.

Production levelling (also called Heijunka), and frequent deliveries (as a result of JIT) to internal customer are key to identifying and eliminating Mura. The use of different types of Kanban to control inventory at different stages in the process are key to ensuring that ‘pull’ is happening between sub-processes. Levelling production, even when different products are produced in the same system, will aid in scheduling work in a standard way that assures lower costs.

To even out work undulations, employees are trained in multitasking. This brings evenness among various work-stations.

However, it may be noted that there is no single method to implement ‘lean management’. It is rather i m p l e m e n t i n g a c o m b o o f va r i o u s TQ M methodologies discussed hereinafter.

Total Quality Management (TQM)

TQM has taken the world by storm and is called the third wave of industrial revolutions.

Definition of quality as per various management Gurus:

=Fitness for the purpose of use ¾ Joseph Juran.

=Quality is conformance to requirements – Philip Crosby.

=Quality is prevention of variations in products beyond permissible limits ¾ Taguchi.

=Quality should be aimed at the needs of customer, present and future ¾ Deming.

=The totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs ¾ ISO 8402: Quality vocabulary.

What quality actually means :

<Well designed product with functional perfection ¾ first time right.

<Providing satisfaction beyond customers’ expectations.

<Excellence in service.

<Absolute empathy with customer.

TQM Culture

Total quality management (TQM) is not only concerned with the quality of the products or services offered by the company to the clients but also with the implementation of TQM culture across the whole gamut of the organisation. There should be presence of TQM in every step and everywhere. Quality should be a way of life across the entire organisation.



Five ‘S’

Five ‘S’ is an auxiliary endeavour to make the work place very much congenial to work by making it neat and clean. In other words, it is carrying out and maintaining a proper housekeeping. Although, it is known that a good housekeeping provides a good working ambiance, doing the same in a meticulous and structured way has been provided in the 5‘S’.

45‘S’ was devised by Hiroyuki Hirano in Japan while trying to improvise upon the production system.

4This procedure, together with JIT and TQM tools enabled Japanese industries to improvise a lot on their productivity.

4Existence of 5‘S’ in Japan could be discovered by the western countries only after 1980s although the same was implemented in Japan in 1950s.

4Toyota implemented 4‘S’ by clubbing the first two stages together.

In Japanese parlance, 5‘S’ stands for and the English meanings thereof are;

uSeiri : sorting

uSeiton: setting in order

uSeiso: sweeping/shinning/cleaning

uSeiketsu: standardizing

uShitsuke: sustaining the practice

Sorting: Only the useful items are retained in the stock/tools cribs. The non – usable/ unwanted items are taken out. Items of different categories are sorted out.

Setting in Order: Items are stacked/ arranged in order, so that they could be easily identified and picked up when necessary. A proper layout plan is devised to have easy workflow/ smoothness in operation.

Sweeping/Shining/Cleaning: The work stations and the stacked items are properly and neatly cleaned.

Standardizing: The entire arrangement is standardized for the benefit of operators / flow process, documented and standardized.

Sustaining: The system thus established is made permanent and followed meticulously. Of course, in case a revision in the process is carried out for betterment, the same is followed till further modification.

The humble 5 ‘S’ can bring about drastic changes at work places, offices, educational institutions, shops, super-markets and everywhere else we can think of. It helps reducing cost substantially while bettering aesthetic and employee morale.

Just in Time (JIT)

Just in time (JIT) is an inventory strategy; a company deploys to increase efficiency and decease wastage by receiving goods/providing them to the work stations only when they are needed for the production process.

This procedure has also originated in Japan. The system relies on ‘Kanban’ signals between two points in the process. It informs production when the WIP (work-in-progress) is ready to be taken by the next work station. This also applies for replenishment of raw materials/parts/stocks at a super-market etc.

In Japanese, ‘Kanbam’ means billboard or signboard. This method was deployed by Taiichi Ohno in Toyota plant in 1953 and there was a massive improvement.

Initially, there used to be a ‘Kanban’ card, containing the specification of the item, which used to be with the operator of a work-station till he had the stock. Once, the stock reached critical zone it was sent to the stores for replenishment. The store in turn used to send the card to the supplier for replenishment and the stock got replenished. Later on, the card was replaced by ERP/SAP generated e-Kanban.

Benefits of JIT

1. Reduction in inventory; reduced locked-in capital.

2. Space economy.

3. Minimum wastage/spoilage/breakage.

4. Fast/logical sequencing between production points.

5. No idling/overburdening of w/stations.

6. Permits multi-tasking.

7. Closer supplier relations.

8. Less chances of stock expiring.

9. Improved performance.

10. Improved quality.

11. Substantial reduction in cost due to above.

Deming’s PDCA Cycle

Systematic and customer focused approach is the basic difference between a ‘TQM’ and a ‘non-TQM’ company. Deming was the person, who changed the whole industrial scenario by his 14 point suggestions. Japan implemented Deming's ideas and became industrially the best in the world. The Emperor of Japan decorated Deming with the ‘Second Order Medal of Sacred Treasure’ in 1960. The Japanese scholars created an annual ‘Deming Prize’ in 1987 in his honor. Deming’s PDCA (Plan, Do, Check,



Act) is by far the best tool available in the context of TQM. As per this system, a manufacturer or service provider is required to improve upon the quality of his product/services consistently. The power of PDCA cycle is such that it compels its owner to solve the problems in a systematic and sequential manner.

qPlan: identify problems, prioritize them, pinpoint the critical one, plan a schedule to achieve target.

qDo: collect data, analyse, identify the cause & take immediate / permanent trial corrective actions.

qCheck: the results of the trials. If unsatisfactory, go back to step 1 or 2. If satisfactory, proceed to step 4.

qAct: document and standardize the revised process, re-train employees and run the revised process. Repeat the cycle.

Six-Sigma

Six-Sigma was propounded by Bill Smith in the year 1986 while working with Motorola. It is a one-sided idea to adapt rigorous process control to achieve defects limited to plus or minus six times of standard deviations. There is a system of award of various belts (master belt, black belt, green belt etc) like Judokas, Karate specialists etc. There are many criticisms to this so called quality tool. Some experts call it ‘much ado about nothing’, while some others term it as a mere ‘eye wash’. However, we shall look into it for some possible benefits.

Defects at various sigma levels:

1 Sigma : 690000 defects per million





6 Sigma : 3.4 defects per million

Continuous improvement planning could be brought into an organisation to achieve correctness up to 6 Sigma level. As it has been observed that achieving 6 Sigma would mean no more than 3.4 parts per million defects are allowable in a product or service. Very few companies in the world claim to have achieved this magical figure. Sigma is a symbol for standard deviation. Companies striving to achieve this goal have to adopt stringent process control.

Zero Defect

The ‘Zero Defect’ concept was strongly suggested by Philip B Crosby in his 14 point steps to attain the right quality. He suggested carrying out various activities to launch ‘Zero Defect Program’.

It is undoubtedly a noble idea to achieve so called

‘Zero Defect’. But, actually even attending Six-Sigma

is a daunting task and it is absolutely impossible to

attain ‘Zero Defect’. However, efforts towards

attaining 'Zero Defects' is always appreciated.

Failure Mode and Effect Analysis (FMEA)

This is a technical tool to assure that no product/

project/ services are allowed to be produced which

may contain any defect or deficiency. Procedure is

followed step by step to ensure that the product is

absolutely in conformance to the required quality

and able to perform its desired operations. It is

possible to understand its voracity if we consider

constructing a bridge, making an aircraft etc. the

salient features of FMEA are listed herein below.

¥FMEA is a process of analyzing risk of failure of a

design, product, process, service etc.

¥It is a pure technical model in that particular area

and is carried out by a team of experts in that

subject.

¥Firstly, the theoretical aspects are thoroughly

checked and debated for any possible error.

¥Errors, detected if any are rectified.

¥A prototype of the model is prepared and put to

various types of tests including simulation, if

necessary.

¥All the measurements are recorded meticulously.

If necessary, such tests are carried out repeatedly.

¥Corrections, required if any, are incorporated and

the tests are carried out continuously.

¥In this process, when the product/ process/

service etc. becomes fool-proof, the total changes

are incorporated and properly documented.

¥This process is carried out on a continuous basis

to eliminate any chances of failure.

Poka Yoke

In Japanese, ‘Poka Yoke’ means mistake- proofing.

This method was invented by Shigeo Shingo.

The method is to introduce some anomaly in two

retrofitting parts so that it could only be fitted in a

particular orientation only.

For example, a computer does never accept a CD

or a pen-drive in a wrong orientation.

Although, this looks to be an insignificant

invention, it has a significant contribution

throughout the world of products.



Quality Circle (QC)

Implementation of total quality system is easier said than done. As per QC model it does not rest with a particular department or section. Various voluntary groups are formed from the interested persons taken from various departments to represent quality circles to be set up. Every group contains five to seven employees from different departments. The people are thoroughly trained and motivated to ensure TQM in their respective areas.

The groups may be formed in the following areas

1. 5'S'

2. Product quality

3. Communication

4. Training

5. Employee welfare

6. Increased productivity

7. Quality administration

8. Employee motivation

9. Quality aesthetic and ambiance.

10.Health, safety and environment.

Salient features of the QCs.

µThere should be continuous support and motivation from the top management.

µThe QCs must have a formal meeting every week to review performance of each team during the past week and to decide the targets for the next week.

µOne of the top level management like CEO/MD must be present in such meetings.

µGood work done by the various quality circles must be rewarded.

µFormation of quality circles shall be of immense benefit to the company.

Kaizen

In Japanese, the term 'Kaizen' means improvement. ‘Masaaki Imai’ made this term famous by authoring a b ook t i t led ‘K a izen’. He w rote : ‘K aizen’ (Improvement) ‘Eno’ (In) ‘Yon’ (Four) ‘Dankai’ (Steps). These four steps are nothing but the PDCA cycle propounded by Deming.

The five main steps to achieve Kaizen are:

¬Team work

¬Increased employee participation

¬Increased high morale infusion by the management

¬Developing quality circles

¬Management’s consistent endeavor towards non-stop improvement.

Under this system all the employees are motivated to provide big or small suggestions for their part of work or anything else on continuous basis. It is not one or two suggestion per month or year. They are encouraged to give at least 100 suggestions per employee per year. Toyota Corporation implemented Kaizen with great care. In 1999, they had 7,000 employees. Toyota got 75,000 suggestions and implemented 99% of those. Kaizen not only helps in improving productivity and product quality, but also in all other aspects of the organisation.

Critical Path Method (CPM)

CPM is an important scheduling tool for effective project management.

CPM was developed jointly by the DuPont Corporation and Remington Rand Corporation for managing plant maintenance projects in 1950.

In CPM, the total project is first broken down into smaller tasks called activities. This is known as break down structure (BDS). Duration of each activity with the preceding and succeeding activities is tabulated. A network of activities with their respective durations is drawn keeping in sequence the preceding and the succeeding activities. The maximum duration path without any float is called the Critical Path, which represents the minimum duration of the project.

Project Evaluation and Review Technique (PERT)

The PERT was developed independently but almost simultaneously with CPM by Booz-Allen and Hamilton as a part of US Navy’s ‘Polaris Missile Submarine’ program along with Lockheed Corporation.

PERT analyses the tasks involved in completing a given project. It provides way to calculate the most likely time to complete even uncertain tasks. A network of the tasks is prepared, which helps in planning and monitoring the project. PERT emphasizes more on time than on cost. It can also cater for very large projects embedded even with uncertain activities.

Now, PERT-CPM techniques are used together to device the best scheduling.

The principle of lean management applies to Construction works as well. Most of the tools like; 5 ‘S’, JIT, PDCA, Zero Defect, FMEA, Poka Yoke, QC, Kaizen etc are applied to project management. This is known as; ‘Lean Construction’. Substantial advantages could be derived by application of lean management principles in Construction works also.



Agile Manufacturing

Agile manufacturing is the next concept after ‘Lean Manufacturing’. ‘Lean’ leans on cutting flab from all possible areas of the manufacturing process. ‘Agile’ believes to keep the entire manufacturing process on tenterhooks by promptly responding to the market demand. It encourages frequent changes in the production schedule to cater as per market needs. Production in small lots is encouraged depending upon customers’ needs. Data is generated as soon as marketing for specific variants of products are booked. This data is shared among various departments of the organisation. Accordingly, production schedule, procurement of raw materials/parts etc are arranged, so that, the product reaches its customer directly within a reasonable period. In this system, the entire production system is made to respond to the changeovers without any loss of time or money.

In production system, there are basically two categories; 'Push system' and 'Pull system'. Push system believes in producing in larger batches and holding the stock for customer's buying. Pull system, on the other hand, depends on manufacturing only after getting confirmed orders from the customers. In 'Pull' system, the product is directly delivered to the customer from the work shop. In 'Push' system, the products are stored on the selves/warehouses for pick up by the customers.

Le-agile Manufacturing

Le-agile is a hybrid of ‘Lean’ and ‘Agile’ systems. Both the systems are combined together to achieve the best results. In fact, in this hybrid system, the products are partially made ready as per ‘Lean’ system. Thereafter, the balance works are carried out as per specific customer requirements.

Conclusions

‘Lean manufacturing’ is undoubtedly a game-changing concept , which tries to reduce ‘Unnecessary’ costs from each nook and corner of the manufacturing process. Lean manufacturing enables reducing cost to a great extent. This system works nicely in the case of mass production. Since the production is taken up based on the anticipated demand, it creates inventory of finished goods.

'Agile manufacturing' advocates manufacturing products only on securing orders. Stress is given on making the whole production process quickly responding to taking up another product. In this way, carrying inventory of finished goods is avoided. Since the product is directly sent to the customer from the shop floor, additional cost of multiple handling, involvement of intermediaries etc. are eliminated.

Some people have compared the ‘Lean’ system with a thin person and the ‘Agile’ system with a sports person. In fact, such comparisons do not hold good. Neither of these systems nor an arbitrary ‘Le-agile’ combo could work as a unique solution in each and every case. For big or high value items like aircrafts, supercomputers etc. the productions have to be taken up on orders only, that is, on ‘Agile’ system. For items like automobiles, furniture etc Le-Agile is the best alternative. In this process, the basic common framework is produced as per the mass production system applying ‘Lean’. Further works are completed as per the specific orders. In case of small value items, items with fewer varieties and the items with stable demands ‘Lean’ method is best suited. Most of our regular use goods are in this category.

It is also to be noted that, these three are no separate sets of procedures. All TQM tools are equally applicable whether the system is called ‘Lean’ or ‘Agile’. In the ‘Agile’ concept, only swift changeability of man/machine is added to the ‘Lean’ system, which is a welcome change. Application of ‘Le-agile’ depending upon the product/demand pattern optimizes customer’s value for money.

Added to these, digitalization of the entire process from sales to ordering purchases, auto scheduling, inspection, billing, shipping, delivery, collection, customer feedback etc plays a vital role today. It increases speed of communication, eliminates errors and human biases, reduces cost, gets customer’s feedbacks and a host of other convenience.

And last but not the least; e-tailing has brought a great change in the Marketing and Supply Chain Management. Most of the intermediaries are done away with. The customer gets the fresh product directly from the shop floor. It has enhanced the two way communication between the producer and the customer to a great extent benefitting both. As a result, cost has come down and reliability has increased substantially.



Nano-finishing of Freeform/Sculptured Surfaces: A ReviewL D Nagdeve, V K Jain, J RamkumarDepartment of Mechanical EngineeringIndian Institute of Technology KanpurKanpur 208016, Uttar Pradesh, Indiae-mail: [email protected]; [email protected]; [email protected]

Abstract

Freeform surface is difficult to define by a single mathematical equation. Freeform surfaces can have any designed shape and often no axes of rotation. These complex geometrical surface shapes are termed freeform surfaces. To achieve high level of surface finish is a challenge especially in complex shaped components, 3-D components and components with freeform (or sculptured) surfaces. Surface finish is one of the most significant factor which affects the life and functionality of a product. Freeform surfaces in medical science, silicon in IC industries, micro channels in micro-fluidics, dies of automotive body panels, turbine blades, impellers of artificial heart pumps and automobile industries need nano-level surface finish as their functional inevitability. For this purpose, flexible finishing tool is required. Belt finishing, vibratory finishing, drag finishing are often used in industries for finishing of freeform surfaces but in these processes uniform surface finish cannot be achieved because of the process limitations. Afterwards, many traditional and advanced finishing processes such as grinding, buffing, honing, ball burnishing, soft and elastic abrasive tool finishing and MR fluid based finishing processes have been developed for finishing of freeform / sculptured surfaces but still we are not able to achieve uniform nano scale surface finish in case of freeform surfaces. To overcome the limitations of the above mentioned processes, researchers are developing new processes and their setups. In this article, censorial review of nano-finishing of freeform / sculptured surfaces has been presented.

Keywords : Nano-finishing; MRP fluid; CIPs; Abrasive; Surface roughness; Freeform surfaces

Introduction

Now-a-days, in manufacturing industries, the term nano-finishing relates with surface integrity which is one of the most important and challenging tasks. New products and materials are being discovered by researchers and they need ultra-precision finishing with appropriate functional requirements such as silicon in IC industries, micro-channels in micro fluidics, optics, moving assembly such as piston-cylinder and bearing in automobiles. Another important field where nano-level surface finish is needed, is medical science where bio implants need nano-level surface finish. Knee joint and hip joint are the devices where surface finish is the most important strategic outcome. Fluid flow resistance, friction and optical losses, and fatigue strength of the above mentioned bio-implants are affected by the surface conditions. Die and mold industries make very complicated and intricate surfaces but the final product quality also depends upon their surface quality. Surface finish enhancement is required during or after fabrication of the components.

Selection of the right kind of manufacturing process is very important for any product. In the same way,

finishing processes are of a major concern to achieve nano level uniform surface finish of the final product. It is very difficult to achieve nano level uniform surface finish in case of freeform surfaces due to many features of freeform surfaces such as non-rotational symmetry, and irregular and complex geometries. Also, generation of tool rotation path for freeform surfaces is equally important for achieving nano range finishing which is not possible in traditional finishing processes keeping a close dimensional tolerance. Hence, it is very important to select appropriate process for finishing freeform surfaces and 3D complex surfaces.

Literature Review

As shown in Figure 1, finishing processes for freeform surfaces can be divided mainly in four classes: Rigid tool based, CNC based, Robot controlled based, and flexible tool based finishing of freeform surfaces

Rigid Tool based Finishing of Freeform Surfaces

Zhong and Nakagawa [1] developed the grinding methods for toroidal mirrors with large curvature





radii and carried out the grinding experiments. Toroidal mirrors made of SiC with large curvature radii were precisely and automatically obtained with good shape accuracy and low surface roughness by using bonded abrasive wheels. The control method and the structure of the grinding system were simple. The time consumed in the manufacturing processes was greatly shortened. The machine used for the experiments was comparatively less expensive and it was not specially designed for the purpose of ultra-precision grinding. Umehara and Komanduri [2] discussed about the magnetic fluid grinding of hot isostatic pressed (HIP) silicon nitride rollers. Surface roughness of about 5 nm was achieved. Different kinds of abrasive and different sizes of abrasive particles were used. High removal rate with B4C abrasive particles and high surface finish with Cr O 2 3

abrasive particles were obtained. HIP Si N has many 3 4

properties like high hardness, low density, good fatigue life, high Young’s Modulus etc. The advantage of this process is that at the contact surface as the polishing takes place then both front and side faces are provided with rounded edges. Kuriyagawa and Zahmaty [3] developed a new system for grinding with a new approach towards the positioning and maneuverability of the earlier diamond based system. The arc envelope grinding method (AEGM) based system (Figure 2) demonstrated excellent grinding performance of aspheric ceramic mirrors. To obtain a better form accuracy, we need an on-machine form-measuring instrument with resolution of less than 10 nm. Baran and Plichta [4]

designed and fabricated multi tool polishing head with independent pneumatic drive system for effective machining of free form surfaces. The multi tool grinding polishing head is composed of six tool groups, in which abrasive discs designed for grinding and polishing are embedded. The head can be successfully used in machining centers.

Huang et al [5] used a robotic grinding and polishing system to automate the manual operation of turbine-vane overhaul. The robotic grinding and polishing system has enabled the overhauled vanes to meet stringent quality requirements such as profile smoothness, surface roughness and minimum wall thickness. The system hasn’t yet been utilized to obtain polishing of other engine components, such as impeller blades. The extension of its applications is a notable area for future research.

Figure 2 (a) Conventional grinding method and (b) AEGM based system

Figure 1 Classification of finishing processes for finishing freeform surfaces

Nowicki and Szafarczyk [6] elaborated the non-traditional honing as a finishing process where profiling and finishing are done on the same machine tool. In this method, abrasive tool which has 4 degrees-of-freedom (DOF), is plastically pressed against the surface. Many sculptured surfaces such as press forming dies, propellers, and screw propellers can be finished using this finishing process. Basically,

2large freeform surfaces of size greater than 1 m are finished by this method. Dynarowski and Nowicki [7] elaborated the non-traditional honing (NH) method and conducted experiments on the freeform surfaces such as concave, and convex using the rules of experimental design. It was found that the total finishing time reduced. In this finishing process, the abrasive tool was elastically pressed against the surface. Robot with more degrees of freedom can be used in the existing process for covering a larger area which will reduce the total finishing time.

Shiou, et al [8, 9] developed a ball-burnishing surface finishing process on a machining center for a freeform surface, say plastic injection mold. The newly designed ball-burnishing tool can be used for both plane surface ball burnishing and freeform surface ball burnishing. By applying the optimal burnishing parameters, the surface roughness improvement of the injection part on plane surface was about 62.9% and that on freeform surface was about 77.8%. However, it may be difficult to make the tools necessary to work on certain geometries. To improve these, a hybrid process combining multitasking and artificial intelligence can be introduced so as to increase efficiency and executability of the final operation even in case of complex geometries.

Dedicated machines have been developed [10,11] such as belt finishing (Figure 3), vibratory finishing, drag finishing etc. In drag finishing system the parts are mounted on a carousel which in turn is equipped with multiple workstations in which usually four to twelve workstations are ‘dragged’ through a circular work bowl filled with grinding or polishing medium. But, in this process, uniform surface finish cannot be achieved because of process limitations.

CNC based Finishing of Freeform Surfaces

Lasemi, et al [12] discussed the state-of-the-art on recent developments in CNC machining of freeform surfaces, including issues such as tool path generation, tool orientation identification, and tool geometry selection that affects the final quality of freeform surfaces. Usually five or seven axes CNC milling machine is used to make and create complex geometries from extremely wear resistant, corrosion

resistant, bio compatible, hard alloys and ceramics. Finishing of these components does not meet the required specifications related to high surface finish. It was observed [13] that five or more axes machining operation gives better results because the tool is always able to maintain a fixed angle between its axes and the work surface, leading to uniform surface finish (Figure 4) compared to the three-axes CNC system. Five axes CNC machine was used [14] for finishing of ceramics femoral component. First they used grinding process, followed by polishing process for removing grinding marks and tiny surface imperfections, and achieved high quality surfaces. They used five axes grinding with toric pins and then five axes polishing with deformable elastic tool with diamond as abrasive. A commercial product known as ‘precessions’ [15], is also used for fine finishing spherical and aspheric surfaces. In this technique, a semi – spherical tool is used for finishing a workpiece in the presence of polishing slurry. A semi spherical tool is coupled with seven axes CNC polishing machine that has been custom designed.

Robot based Finishing of Freeform Surfaces

Richard and Walker [16] reported the development

Figure 3 (a) ROSLER oberflachentechnik GmbH, compact drag finisher and (b) conventional belt finishing technique

Figure 4 (a) 3-axes CNC milling giving non-uniform finish and (b) 5-axes CNC milling giving more uniform finish





of a novel industrial process, embodied in a new robotic polishing machine, for automatically grinding and polishing aspheric optics. The machine is targeted at meeting the growing demand for inexpensive axially symmetric but aspherical lenses, mirrors, non-axisymmetric and conformal optics of many kinds, planarization of silicon wafers and associated devices, and controlling form and texture in other artefacts including prosthetic joints. An automated robot system was developed [17] for p e r f o r m i n g f i n i s h i n g o p e r a t i o n d u r i n g manufacturing of various dies and molds. It is usually found that a number of robotic systems are available for manufacturing of dies and molds, but they have not been developed to perform finishing operation, which is usually carried out manually, consuming up to 30% to 40% of the total manufacturing time. The main drawback of the process is that irregular objects require highly precise inspection and finishing, and to make an automated process for the same is difficult. Most of these problems were overcome in robotic systems containing more degrees of freedom for precise intermediate inspection and appropriate finishing. Researchers [18-20] attached grinding wheel to a robotic arm so that it can move along the freeform surface depending on the degrees of freedom of the robotic arm. In the finishing process, the main limitation is that finishing is dependent on the degrees of freedom of robot and only 2 degrees-of-freedom lead to a small contact area. This process can not cover the whole finishing area of the workspace and hence the process is more time consuming. Brecher, et al [21] have developed a six axes industrial robot with force controlled orbital head for finishing freeform surfaces where finishing is performed in various stages. Diamond paste was used as the final polishing medium. Different stages were used for finishing such as grinding (first stage), lapping with brass ring (second and third stages), polishing with plastic ring (fourth and fifth stages), and at last polishing with felt pad (sixth stage).

Flexible Tool and MR Fluid based Finishing Processes

A flexible abrasive tool [Figure 5(a)] was made of thermosetting polyurethane elastomer with coating of aluminum oxide abrasives for automatic finishing of curved surfaces on a CNC machine [22]. The ball end type tool has the ability of conducting finishing operation and deforming itself according to the shape of surface to be finished. Sooraj and Radhakrishanan [23l developed the polymer coated abrasive termed as elastic abrasive [Figure 5(b)] and

used for nano finishing of hard workpieces. Using the elastic abrasive, impact erosion can be minimised and flow of the fluid is also reduced. Final surface roughness achieved was 0.0267 μm from an initial surface roughness value of 0.182 μm. Brinksmeier and Riemer [24] have used a form grinding process where the shape of the grinding wheel is an inverse replica of the workpiece to be finished. In this process, pin type and wheel type polishing tools were made of polyamide to improve the surface roughness of structured molds. Abrasive polishing of V-grooves requires specially shaped polishing tools which do not have flexibility in terms of the shape of the component. In this process, a separate tooling is required for each workpiece. Wu, et al [25] developed a grinding centre (GC) tool with an elastic ball type wheel. In this process, only cusp height generated in cutting process with a ball end mill is removed. Therefore, it was possible to conduct polishing without changing form accuracy generated in the preceding operation on an NC machine. This highly accurate polishing technique is helpful in polishing of freeform surface which is contained in die and mold.

Jain, et al [26] investigated the abrasive flow finishing of complex geometry using FEM analysis. Theoretical models were developed for material removal and surface finish by AFF process and the same were compared with the experimental results. It was concluded that material removal is significantly affected by the extrusion pressure and it proportionally increases. It was also concluded that increase in DRa (change in Ra) value for conical surface was less as compared to cylindrical surface while keeping same extrusion pressure and number of finishing cycles. In the same way, Sarkar and Jain [27] did nano-finishing of femoral component which had complex profile by AFF. Surface roughness of 42.9 nm to 62.5 nm was achieved on the different curvatures of the femoral component.

Jacobs, et al [28, 29] developed a magnetic field assisted method for producing complex optics with figure accuracy less than 50 nm and surface

Figure 5 (a) Schematic representation of flexible abrasive tool and rigid tool during finishing and (b) schematic of elastic abrasive

roughness less than 1 nm. On the setup designed and fabricated by them, it was possible to conduct the screening experiments on different MR fluids and on different materials. Tricard, et al [30] developed a new technique for finishing concave or freeform surfaces using MR fluid jet. In this technique, a round magnetized jet of MR fluid is used. MR fluid jet is highly collimated, coherent and long stable in the presence of magnetic field (Figure 6). This type of arrangement is necessary for steep concave workpiece. Workpiece is kept at the top of the jet and it is continuously rotated or swivelled according to its shape and size. This technique can be used to finish concave surface of glass and single crystal silicon wafer, including the inaccessible areas. Singh, et al. [31] developed a setup for nano-finishing of 3D surfaces using ball end MR finishing tool. In this setup, magnetic field is provided by electromagnet and MR fluid is supplied through the central rotating core. It is observed that in case of non-magnetic materials, the magnetic lines of force are not attracted towards the workpiece and it does not make a very good shape of ball end of MR polishing fluid because majority of the magnetic lines of force are diverted from inner core to outer core at the tip of the tool and MR fluid becomes stiffened along these magnetic lines of force. It is concluded that the present process is more suitable to finish non-magnetic materials. Singh, et al [32] developed a nanofinishing process using ball end magneto-rheological (MR) finishing tool for finishing 3D

workpiece surfaces. In this process, a ball end shape of MR polishing fluid is generated at the tip surface of the rotating tool which is used as a finishing spot. The performance of the ball end MR finishing process was successfully demonstrated on the typical 3D ferromagnetic milled workpiece surface. The surface roughness was reduced to as low as 16.6 nm, 30.4 nm, 71 nm and 123.7 nm on flat, 30°, 45° and curve surfaces of the 3D workpiece, respectively. The variation in magnetic normal force can be minimized by providing a tilting motion to MR finishing tool. This can be done by addition of a rotary axes in the present finishing setup, so that the tool tip surface can be made always perpendicular to the 3D workpiece surfaces during the finishing operation. This will produce uniform magnetic normal force and flux density zone irrespective of 3D workpiece surface and will result in uniform finishing over 3D surfaces. This would lead to a better surface finish even in case of curved surfaces.

Sidpara and Jain [33] developed a magneto-rheological fluid based finishing tool [Figures 7(a)-(b)] for nano finishing of knee joint implant, which has complex freeform surface. A high strength permanent magnet was used to produce the magnetic field. The finishing tool was attached to the tool head of 3-axes CNC milling machine. MR fluid gets stiffened in the presence of magnetic field and forms a hemispherical shape. Different types of MR fluids (that is, oil, water or chemical based) were prepared as a medium to finish the knee joint implants (made of Titanium alloy). It is concluded that oil based MR fluid is not effective for finishing hard materials. In this research work, final Ra of 28 nm had been achieved from initial Ra of 268 nm in 16.4 hours of finishing on one face of titanium alloy implant. But this process is more time consuming and produces non-uniform surface finish on four different faces.

Basera and Jain [34, 35] used magnetic abrasive finishing (MAF) process to finish the surface of the

Figure 6 Schematic representation of MR jet finishing process

Figure 7 (a) Schematic representation of MRFF process, (b) photographic view of MRFF process [32] and © photograph partially finished tooth



bearing which has complex configuration (curved and conical). The experimental work was also focused on reducing cycle time of finishing of taper roller bearing. Earlier the finishing time was observed as 6-20 h depending on the level of damage of the bearing surface. By implementing the methods and processes described in this paper [34], the authors were able to achieve surface finish as low as Ra =36.5 nm from initial Ra = 271.5 nm without any surface damage within 24 min. Sarkar and Jain [36] developed a flexible tool which was analogous to the ball end mill by curing polydiemethylsiloxane (PDMS). Flexible tool follows the path on the curved surface. A boul shaped copper workpiece was finished. Final finish obtained was 53 nm from the initial roughness of 241 nm with finishing rate of 69 nm/min. Different sizes of abrasive particles were used to improve the surface roughness value of the workpiece. Yamaguchi and Graziano [37] did nano-finishing of knee prosthesis made of cobalt-chromium-molybdenum (Co-Cr-Mo alloy) using magnetic abrasive finishing (MAF) process. Finite element magnetic field analysis was done. They designed and fabricated the knee holder and used six-axes robot arm where they placed the knee implant. A conical pole tip was attached to an electromagnetic coil and kept it in front of the knee and maintained the clearance of 1 mm. Iron particles and diamond particles were used as polishing tool. In the same way, Baghel, et al [38] polished the artificial crown for tooth which is one of the examples of freeform surfaces. They used three-axes CNC milling machine for this purpose. The initial surface roughness value Ra was 2.79 µm in X direction and 3.18 µm in Y direction. After finishing final surface roughness Ra value obtained was 0.030 µm and 0.057 µm in X direction and Y direction, respectively. Before finishing the area roughness value was 1.43 µm which got final surface roughness value approximately 0.008 µm. Since the profile of crown was convex where the brush was not able to reach uniformly on the upper surface of the crown. Hence, the distance between the brush and upper surface of the crown was not constant and surface was not uniformly finished. In Figure 7 (c), the polished spot on the crown can be clear seen. Sidpara, et al [39] described the fabrication and finishing processes (magnetorheological finishing and elastic emission machining, say MRF and EMM) of mirrors such as flat, cylindrical, elliptical and toroidal followed by many steps such as grinding, etching, lapping, and polishing. These processes are able to achieve surface roughness of a few angstrom level which is

required in Synchrotron beamline for good focusing properties and good reflectivity of X-rays. However, there are few challenging issues related to metrology because measurement of surface roughness and slop errors require specialized instruments on the specified level of measurement. Kumar, et al [40] developed a fixture for artificial knee joint which is one of the examples of freeform surfaces and carried out the experiments on it. There was a magnetic fixture having eight magnets in a circular path in the rotational-magnetorheological abrasive flow finishing (R-MRAFF) setup. Mesh size and extrusion pressure were selected as variable parameters. It was observed that the process was useful for any complex shape but the tooling is needed for that particular workpiece. It has also been noted that surface roughness was not uniform. In conclusion it may be said that there is a need of improvement in workpiece fixture for getting uniform surface finish.

After studying the relevant research work it can be suggested that the polishing medium could be improvised and used for experimental studies. Also, it is suggested that by changing the design of the experimental setup and its comprising parts, better results can be obtained. In magnetic field assisted finishing processes, finishing can be improved by proper arrangement of the magnets, so that the required uniform magnetic field could be achieved at the upper surface of the workpiece to be finished. By controlling the magnetic field strength, we can control the forces acting on the upper surface of the workpiece.

Conclusions

Following conclusions can be made from the above literature survey :

µFive or seven axes CNC machines are able to produce uniform finish but in case of freeform surfaces in nano-meter range, it is still not possible due to their limitations.

µMechanical finishing and belt finishing have been extensively used in the industries but they are unable to achieve the uniform surface finish due to process limitations.

µFinishing of freeform surfaces has been a great challenge in the field of biomedical science.

µControlling the forces during finishing of freeform/sculptured surfaces is one of the most important parameters, and it is difficult to achieve. It affects the final surface finish of the workpiece.



µ

surface is a challenging task.

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Some Strategies for Achieving Green Manufacturing U S DixitDepartment of Mechanical Engineering, Indian Institute of Technology Guwahati 781039, Assam, India.e-mail: [email protected]

Abstract

General public and industries have started to recognize the importance of environmentally friendly manufacturing, popularly known as green manufacturing. Green manufacturing aims at reducing the consumption of natural resources as well as the pollution. Some strategies are discussed for achieving green manufacturing. This can be done by improving the existing technologies, for example eliminating or minimizing the use of cutting fluids, and replacing the existing technologies by greener technologies, for example, developing a thermal autofrettage process in lieu of hydraulic autofrettage. Modeling and optimization of processes in the framework of cloud computing and cloud manufacturing can contribute a lot towards green manufacturing. Waste minimization, reuse, recycling and use of biodegradable materials should be paid attention. It is concluded that green manufacturing requires significant attention of management for changing the existing practices, but continuous research and development is also needed.

Introduction

Green manufacturing, environmentally friendly manufacturing, environmentally conscious manufacturing and sustainable manufacturing are the buzzwords of modern age. Industries as well as the general public are becoming concerned about the environment. This is an encouraging trend. However, the interpretation of these words is subjective. It is important to understand the meaning of these words and more important is the understanding the strategies to put these into practice. Green manufacturing comprises the manufacturing practices that are benign to environment. It aims at conserving the natural resources and energy. It also aims at minimizing the pollution. The new trend is to develop life-cycle thinking. The job of a manufacturer is not limited to manufacture a product and sell it. The manufacturer should take the responsibility of the product from its inception to the disposal. This requires proper service and maintenance till the product can perform intended function satisfactorily. After the product's life is over, arrangement should be made for proper disposal of the product through recycling or reuse. It is also essential that a product should be environmentally-friendly not only during manufacturing stage, but also during its operating life. A car that requires high energy input during its manufacturing but provides good mileage is better than a car requiring low energy input during its manufacturing but providing poor mileage.

Environmentally friendly manufacturing and

environmentally-conscious manufacturing are used synonymously with green manufacturing [1,2]. On the other hand, sustainable manufacturing considers environmental, economic and social factors together. Sustainability is defined as the ability to meet the demands of present without sacrificing the requirements of future generations. It is not enough to have environmentally-friendly manufacturing, it should be economically viable[3]. For example, today the cost of electricity generation by solar power panels is expensive in comparison to coal-based power generation. There is a need to develop technologies that will bring down the cost of solar power such that the consumers will be naturally inclined to use solar power without any government subsidy. Social factors are also important in s u s t a i n a b l e m a n u f a c t u r i n g . S u s t a i n a b l e manufacturing should consider social issues such as employment generation, societal development and health of the consumers. A product that does not offer good life style should be discarded even if is environmentally-friendly and economically viable. Sustainable manufacturing makes a balance between environment, economy and society. The main focus of the green manufacturing is the environment, but it helps to achieve the goal of sustainability also in a big way.

The present article discusses various aspects of green manufacturing and some practical ways to achieve them. In a very concise manner the green manufacturing can be defined in the following way.



‘Green manufacturing comprises the strategies of manufacturing that aim at minimizing the exploitation of resources as well as the generation of waste’. Subsequent sections are organized keeping this definition in mind. The description is supported by exemplars.

Minimization of Pollution during Manufacturing

Manufacturing involves converting raw material into useful product. During manufacturing processes, often a number of pollutants are produced. Revolutionary and evolutionary improvements in technology are required for eliminating or at least reducing the pollution during manufacturing. A number of examples can be cited, where there is ample scope for improving the manufacturing practices. Here, a few exemplars will be discussed.

One of the most widely used manufacturing processes is machining. It is a subtractive manufacturing process and a lot of material is wasted in the form chips, but often this process is unavoidable due to complexity and precision of the product. For the efficient conduct of the process, cutting fluid is used, which acts as coolant and lubricant. At the same time, the cutting fluid helps in chip disposal. Petroleum based cutting fluids are common, but they may cause asthma, respiratory irritation, pneumonia, skin disease or even cancer to the operator. Waste cutting fluid pollutes soil and

water. Due to harmful effect of the environment, dry machining is gaining popularity. However, it may not be appropriate solution all the time. There have been some attempts to minimize the use of the cutting fluids in machining. One way is use mist lubrication[4,5]. However, mist is also harmful for the health. The permissible exposure level of the mist

3in air is 5 mg/m as per Occupational Safety and Health Administration (OSHA) standard. In coming

3days, this limit may be reduced to 0.5 mg/m . Several researchers have worked on minimum quantity lubrication (MQL). In MQL, the consumption of the cutting fluid ranges from 50 to 500 ml/h[6]. There have been attempts to replace the petroleum based cutting fluids by biodegradable cutting fluids[7,8]. However, MQL system requires attachment consisting of a pump and its cost effectiveness as well performance should be assessed.

Sarma and Dixit[9] have observed that cutting fluid can be replaced by compressed air cooling. Figure 1 shows the drastic reduction of tool flank wear as result of compressed air cooling during the machining of grey cast iron using ceramic cutting tool. Compressed air is easily available in a typical workshop. Sarma[10] has also carried out economical analysis and found it an effective technique. The setup for achieving compressed air cooling is simple and does not require any significant cost.

Figure 1 Progression of tool flank wear with cutting time (a) dry turning and (b) air-cooled turning of grey cast iron with ceramic tool at high cutting speed. with permission from Sarma and Dixit (2007). Copyright (2007) Elsevier



Figure 2 A schematic of a setup for thermal autofrettage

Metal forming processes use lubricant and invariably the metal forming machines use hydraulic systems. Hydraulic oil and sound generated by hydraulic power pack are not healthy for the environment. One way is to think for innovative solutions. For example, at Indian Institute of Technology Guwahati, a substitute to hydraulic autofrettage has been proposed. In hydraulic autofrettage, the pressurized hydraulic oil creates inhomogeneous plastic deformation in a hollow cylinder or spherical vessel. When the hydraulic pressure is released, the beneficial compressive stresses are produced on the inner surface of the cylinder or spherical vessel. The same objective can be achieved by means of thermal stresses[11]. A schematic of the setup for thermal autofrettage has been developed for the thermal autofrettage of the cylinder and is shown in Figure 2.

Another emerging technology in metal forming is incremental forming[12], although it has old roots. Rolling is a type of incremental technology, where the

shape changes takes place continuously along the length of the product. Manufacturing of large sized deep drawn products can be carried out using incremental forming.

Welding is another widely used manufacturing process. Gas welding and arc welding processes are more common. Usually, the flux coated electrodes are used. The fumes produced in welding are harmful for the operator and environment. Radiation affects the eye side of the operator. Unfortunately, the research in welding technology is focusing on obtaining the better weld-quality and scant attention has been paid to the safety and health of the operators. In a way, submerged arc welding can protect the operator from the harmful effect, but at the present stage of technology, it cannot substitute common welding operations using gas and arc welding. Friction welding[13] and friction stir welding[14] are relatively greener manufacturing processes.



Minimization of Resource Input

Manufacturing is a multi-variable optimization problem. The goal is to minimize the deviation between the desired product and manufactured product as much as possible with the existing constraints. The important decision variables are the type of process, the raw material quality, raw material quantity and process parameters. Raw material, energy and auxiliary materials are the major resources. Appropriate selection of process and its parameters can minimize the resources. For example, machining is a widely used manufacturing process, but it wastes a lot of material in the form of chips. If a rod of 20 mm diameter is to be reduced to 10 mm diameter, 75% of the material will be wasted in the form of the chips. Rod rolling can achieve it without any loss of the material. However, the facility for the rod rolling may not be available at each and every factory or workshop. If a low capital intensive rod rolling setup (preferably portable) can be developed, it will reduce a lot of material wastage. It is here that the innovative product development becomes very relevant.

There is already a lot of research input in near-net shaped manufacturing and thin-walled machining. Recently, 3D printing technology[15] has gained a lot of importance. The process is attractive because it is basically an additive process, instead of subtractive. This implies that there is lesser wastage of raw material. The pertinent question is can it handle various type of materials and product sizes.

Figure 3 A concept of cloud computing based optimization of machining processes. with permission from Ref 16. Copyright (2012) Springer.

Process modeling and optimization has an important role to play in minimizing resource input. It is not possible to have modeling experts in each and every organization. Moreover, physics based modeling is always not successful in mimicking the behavior of a manufacturing process. Soft computing based techniques and internet can play an important role in supporting or sometimes substituting the physics based modelling. Figure 3 shows a concept of cloud computing based machining optimization[16]. Main database and code can be kept at a central place and information can be retrieved by different factories. Fine tuning of results will still be required and factories should be able to send back the information to central server. This concept of using cloud computing can be extended in the form of cloud manufacturing, where the organizations can share the resources and technology for achieving the goal of green manufacturing. Pollution control and waste disposal can be easily managed in a collaborative way.

Improving Energy Efficiency

The manufacturing processes require a lot of energy. Energy generation itself consumes a lot of resources and invariably pollutes the environment. A manufacturing process may apparently look very clean, but may not be green from the point of view of energy consumption. Solar energy is considered green. However, fabricating of solar panels requires caustic chemicals such as sodium hydroxide and hydrofluoric acid. It is always better to minimize



energy consumption, thus saving the taxing of environment through energy generation. For that purpose, the machines and processes should be energy efficient. There is a need to continuously improve the processes and machines. In Japanese language, it is called kaizen. Through research and development, the efficiency can be improved in an unimaginable manner. When the steam engine was invented, its efficiency was around 0.5%. Later on due to continuous improvement in the design, the efficiency rose to 30%. Another example can be seen from the development in the laser technology. CO 2

laser was invented by an Indian C K N Patel working in Bell Laboratory. Its efficiency was 0.0001%. Nowadays, CO lasers have an efficiency of around 2

30%. The moral is that continuous research and development can achieve the goal of green manufacturing in a big way.

Companies should use renewable energy wherever it is possible. They should make use of waste-heat recovery as well. There is a need to carry timely energy audit. Automatic energy saving devices should be used. One cannot rely only on the awareness of people. In some hotel rooms, a simple technique is employed for energy saving. Once a room is opened, the key has to be inserted in a proper place that activates the main switch. As soon as the key is removed, for example when the guest comes out of the room, main switch opens and all electrical gadgets switch off. Compare this with a situation, where an instruction is written in the room ‘please switch off the lights while going out of the room’. Similarly nowadays automatic water taps are very common, where the flow of water continues only if the hand is placed below the tap. Compare this which a situation where an instruction is displayed in the wall: ‘Please close the tap after washing your hands’. The point to be understood from these examples is that the system should be improved. A system should automatically encourage the individual to follow good practices. These ideas were propagated by quality guru Deming[17]. He used to believe that achieving quality is mainly the responsibility of the system. ‘The workers are handicapped by the systems, and the system belongs to the management’. ‘Slogans, exhortations and posters with targets to be met (without providing the means to meet them) are directed to the wrong people. They take no account of the fact that most of the trouble comes from the system’. In nutshell, management should develop a system that automatically accomplishes the task of energy efficiency enhancement.

Waste Minimization and Disposal

In spite of reducing the waste, some amount of waste is inevitable. The waste can be suitably utilized. For

example, the fly ash produced in thermal power plants can be used in road construction. The chips produced in the machine shop floor can be used to make composite materials. At present, one group of researchers at Indian Institute of Technology Guwahati is exploring the possibility of preparing epoxy based composite utilizing the waste chips. The other group is using the bamboo and epoxy to make composites.

Lean manufacturing practices help in the minimization of waste (muda). Ohno[18] (1912-1990) of Toyota has identified the following seven types of muda: ( i ) defects in products ; (ii)overproduction of goods; (iii) inventory; (iv)unnecessary processing; (v) unnecessary movement of people; (vi) unnecessary transport of goods; and (vii) waiting by the employees. Womack and Jones [19] have added eighth muda, namely, design of goods and services that do not meet user's need. Lean manufacturing identifies the muda and attempts to eliminate it.

Change of manufacturing process can affect the quality of the waste. For example, instead of drilling a hole, trepanning can be employed. Trepanning provides the waste material in the form of sludge of metal, which can be easily disposed. The design for zero waste aims at designing the product as well as manufacturing processes for minimizing the waste to the extent possible. This will involve the use of biodegradable materials and eco-friendly processes.

Reuse and Recycling of the Product

When the life of a product is over, it can be repaired. Many products can be made to function like a new product after the repair. In 1980s, HMT was a leading manufacturer of mechanical watches. Service centers of HMT used to accept old and defective mechanical watches for repair. Many times parts used to be replaced by new parts. After the repair, the watch used to function like a new watch. Although the cost of servicing used to be higher than open market servicing, this strategies was beneficial for customers as well as company. Company earns good will by offering such type of support for the life time of the product.

Sometimes, it is not possible to reuse the product. In that case, it should be possible to recycle the product. The companies can make a policy to collect the packaging material of the product as well as defective product. Some cold drink manufacturing companies collect the used water. Several companies offer buy back option. It is easier for a company to recycle the



product rather than leaving it to someone else.

For achieving the goal of reuse and recycling, product design has to improve. Design for reuse and design for manufacturing are the common terms used. Design for reuse means designing the products so that the product as a whole or its components can be used in later generation of products. Design for remanufacture means having the provision for remanufacturing.

Use of Environmental-friendly and Biodegradable Material

In India, there was a good tradition in villages. In community feast, the food used to be served on banana leaves or plates made from the leaves of some trees. After using them, they used to be dumped somewhere to naturally degrade. Although, this tradition is continuing till today, it is being taken over by the use of plastic and paper plates. There is a need to rejuvenate such type of practices to use bio-degradable material.

The leaf of areca nut tree is a hard material with a good tensile strength. It is used to manufacture decorative veneer panels and picture mounts[20]. It is used for making plates and bowls as well. There are some foot operated machines to make plates and bowls. In IIT Guwahati, hand operated machines were developed[21]. Two types of machines were developed. One was the electricity-based machine for heating the die and punch to required temperature. In gas-based machine, die is heated by

Figure 4 A hand operated machine for making plates from areca nut leaf

liquefied petroleum gas (LPG) (one LPG burner is fitted below the machine) but punch had to be heated by electricity. This project was sponsored by a non-government organization Dhriiti, New Delhi. The hand operated plate making machine from areca nut leaf is shown in Figure 4.

In Assam, in certain villages, water hyacinth is used for making hats, bags and mats. Water hyacinth can also be used to clean water and create biomass. Similarly, there is extensive use of bamboo and cane for making furniture. There is a need to encourage such type of industries.

Conclusion

Green manufacturing is not any technology, but is a management philosophy. Almost everyone understands the literal meaning of green manufacturing, but very few understand how to implement i t . For the success of green manufacturing, strong awareness is needed among the mangers and designers. Management should carry out energy, health and safety audits from time to time. Pollution to environment should be minimized. The companies leaving the pollutants should be responsible for replenishing the damage. For example, they should be forced to carry out plantation. ISO:14000 can help in achieving the goal of green manufacturing. ISO:14000 standards are designed to cover environment management systems, environmental auditing, environmental performance evaluation, environmental labeling and life-cycle assessment. ISO:14000 specifies that an environmental policy considering the interest of the public must exist in the organization. Research and development is also essential for developing greener technologies. There is need to carry out research in waste minimization and waste utilization. Companies should be responsible for the entire life cycle of the product. Government regulation and public awareness is needed for promoting green manufacturing.

Green manufacturing may not always incur extra cost. In fact when good practices, like just in time (JIT) are followed, it may result in the cost saving. One of the benefits of the green manufacturing would be reduced wastage. Moreover, it will save valuable resources.

Acknowledgement

The author thanks Prof A Unal for discussing various issues of sustainability particularly design for zero waste using biodegradable material.



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Production Engineering Division Board(2015-2016)


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