Integration of ECQFD and LCA for enabling sustainable product design in an electric vehicle manufacturing organisation

Abstract

In the early stages of product development, designers need to take environmental performance into account together with traditional design objectives. Sustainable products are products that are fully compatible with nature throughout their entire life cycle. This paper presents a case study in which the integration of environmentally conscious quality function deployment (ECQFD) and life cycle assessment (LCA) has been applied to enable sustainable product development of an electric vehicle. In this study, ECQFD has been used to handle environmental and traditional quality requirements of the product, whereas LCA has been used for assessing the environmental impact of products and processes. A cost model has been developed by integrating production and environmental costs as well as the technical status of an old part product for reuse. The results obtained from the case study reveal that integration of ECQFD and LCA considers the equal importance of environmental requirements to the traditional requirements of cost and quality thereby ensuring sustainability in product design in an electric vehicle.

Keywords:

• sustainable product development
• environmentally conscious quality function deployment
• life cycle assessment
• environmental cost
• design for environment

1. Introduction

Sustainable products provide the greatest global environmental, economic and social benefits and are measured over their entire life cycle, from raw material extraction to final reuse or disposal. Historically, the manufacturing sectors have always played an important part in any economic or societal growth. Therefore, it is imperative to have sustainable manufacture. Sustainable manufacture is composed of three sub-elements: sustainable product, sustainable manufacturing systems and sustainable manufacturing process. The global automotive industry has developed many new technologies to help the sector play its part in the move towards a low-carbon economy. Electric and hybrid vehicles, along with fuel efficient technologies for diesel engines, are key ‘clean technology’ that has emerged in the recent years and will not only enable the car industry to produce cars with significantly lower emissions, but will also provide the consumer with a wider choice when it comes to sustainable transportation. The environmental burden from consumption is growing and eco-efficiency improvements at the product level are proving insufficient to cope with volume growth at the macro-economic level (Robbins 1999). To achieve a real impact on reducing product-related environmental impacts like reducing waste and emissions throughout the life cycle, environmental considerations should be built into product development at the earliest opportunity and customers should be steered towards the greener options (Charter and Belmane 1999). As standards and accepted methodologies have evolved in economic, environmental and societal performance evaluation, few companies have begun to publish integrated sustainability reports (Fiksel et al. 1998). When resources are limited and consumers' decision-making is driven by both environmental awareness and price, businesses need to account for their environmental and social impacts accurately and develop new ways to communicate the sustainability message to consumers and key stakeholders. A more environmentally viable strategy in terms of preserving resources and energy is the reuse of used parts, sub-assemblies or entire products. However, the decision of reusing old components of a used product confronts many uncertainties such as the quality level of the used components and the economic aspect of reusing them compared to producing a new component. Reuse of parts in existing products is always a more environmentally friendly option than either making new parts or using recycled parts. Life cycle assessment (LCA) is now an essential tool to help companies move towards sustainable production and consumption, as well as achieve financial return. LCA is an evaluation of multiple product environmental benefits over the life of the product from raw materials extraction to final product disposition.

Traditionally, manufacturers focus on how to reduce the cost that the company spends for material acquisition, production and logistics, but due to widespread consciousness of global environment problems and environment legislative measures, manufacturers should take environmental considerations into their decision-making process of product development (Park and Seo 2003). The traditional quality function deployment (QFD) process uses a two-dimensional matrix: listing customer requirements (CRs) and technical requirements (TRs). In environmentally consciousness quality function deployment (ECQFD), a third dimension is added to the QFD matrix, covering the environmental aspects in the form of environmental metrics (EMs) (Kaebernick et al. 2003). The EMs are used to evaluate the customer requirements (EM-CRs) and the technical requirements (EM-TRs) on their environmental impact perspective. In this case study, the integration of ECQFD and LCA has been done to an electric vehicle for enabling sustainability in the process of product development.

2. Literature survey

The literature survey has been done from the perspective of sustainable product development, ECQFD and LCA. Pujari and Wright (1996) have developed a qualitative study of environmentally conscious product design strategies of selected companies in Germany and Britain. Zhang et al. (1997) have presented a state of review on environmentally conscious design and manufacturing concept by updating some general information, guidelines and references for research and implementation. The authors also provide the more clear definition of the term environmentally conscious design and manufacturing and a brief future trend analysis. Azapagic and Clift (1995) have presented a novel approach of application of linear programming modelling to LCA to analyse and manage the environmental performance of a complete product system. The proposed model is used to solve the problem of allocation of environmental burdens in the inventory stage of the LCA, and also enables the investigation of environmental optimum of the system. Sarkis (1998) has presented an integration of design for the environment, total quality environmental management, life cycle analysis, green supply chain management, and ISO 14000 standards and their attributes into a strategic assessment and decision tool using the systems with analytical network process technique for evaluating the environmental consciousness of the operational and strategic decisions for environmental managers and businesses.

Andersson et al. (1998) have presented the feasibility of integrating the concept of sustainability principles and the methodology of LCA to achieve an operational tool that incorporates sustainability in product development and strategic planning. Bogard et al. (1999) have presented the application of LCA to analyse the desirability of replacing lead with a composite of tungsten and tin in projectile slugs used in small arms ammunition at the US Department of Energy training facilities for security personnel. The analysis includes the consideration of cost, performance, environmental and human health impacts, availability of raw materials and stakeholder acceptance. have clearly shown that the application of LCA avails advantages that outweigh disadvantages in replacing lead with tungsten–tin in small-caliber projectiles at Department of Energy training facilities. Gungor and Gupta (1999) have presented a survey of issues in ‘Environmentally conscious manufacturing and product recovery’. This methodology involves integrating environmental thinking into new product development including design, material selection, manufacturing processes and delivery of the product to the consumers, plus the end-of-life management of the product after its useful life. Tukker (2000) has presented LCA as a tool in environmental impact assessment (EIA). The author has shown the differences between EIA and LCA, and concluded that LCA is an analytical tool specifically designed to assess the environmental impacts relating to the whole production chain of a good, whereas EIA is a procedure that has to support decision-making with regards to environmental aspects of a much broader range of activities. Emblemsvag (2001) has presented a method called life cycle costing methodology by employing the comprehensive activity-based LCA method. The author has conducted a real time study to present the method and has illustrated an implementation including the results and discussion of the benefits.

Senthil Kumaran et al. (2001) have presented a novel model called life cycle environmental cost analysis (LCECA) to include eco-costs into the total cost of the products. The presented LCECA model identifies the feasible alternatives for cost-effective and eco-friendly parts/products. They have attempted to incorporate costing into the LCA practice. Laestadius and Karlson (2001) have presented the eco-efficient products and services through LCA in Research and Development by conducting a case study in an organisation. Their case study was aimed to analyse to what extent, the environmental management tool LCA is perceived as efficient within the case organisation. Khan et al. (2002) proposed a holistic and integrated methodology called GreenPro-I for process/product design by combining the traditional LCA approach with multi-criteria decision-making methods. The proposed methodology is simple and applicable at the early design stage and is more robust against uncertainty in the data. Kaebernick et al. (2003) have presented the integration of environmental requirements into every single stage of product development from the very beginning, leading to a new paradigm for sustainable manufacturing. The authors have developed some of the tools for individual stages in the product development process. These tools form the part of an overall concept for sustainable product development. Park and Seo (2003) have presented a LCA methodology for the product concept by grouping products according to their environmental characteristics and by mapping product attributes into environmental impact driver index. The authors have verified the relationship statistically by exploring the correlation between total impact indicator and energy impact category, then a neural network approach is developed to predict an approximate LCA of grouping products in conceptual design.

Masui et al. (2003) have presented a methodology called quality function deployment of environment for environmentally conscious design in the early stage of product development. The proposed methodology by the authors incorporates the environmental aspects into QFD to handle both traditional and environmental quality requirements. Pflieger et al. (2005) have presented an investigation about the contribution of LCA to global sustainability reporting of organisations. The authors have shown the results of impact assessments as central parts of an LCA are a good basis for creating significant indicators for sustainability reports. Giancarlo (2005) has presented a new competitive business strategy through global efficiency improvement by matching ‘environmental performance’ and ‘quality performance’ within a continuous improvement environment. ISO 14040:2006 describes the principles and framework for LCA including the definition of the goal and scope of the LCA; the life cycle inventory (LCI) analysis phase; the life cycle impact assessment (LCIA) phase; the life cycle interpretation phase; reporting and critical review of the LCA; limitations of the LCA; the relationship between the LCA phases; and conditions for use of value choices and optional elements. Pun (2006) has presented the needs and determinant factors, tools and methods of environmentally responsible operations in the areas involving an environmental operations management interface. The author has presented six typical environmentally responsible operation tools, and the findings of a literature review, of selected journal articles on environmental management and related areas from the year 1994 to 2003.

Sadiq and Khan (2006) have proposed an integrated methodology for process design to guide decision-making under uncertainty by combining LCA with multi-criteria decision-making tools. The authors proposed a methodology called GreenPro-I to estimate environmental risks/impacts associated with life cycle of products, processes and services. Basson and Petrie (2007) have presented an approach for the integrated consideration of both technical and valuation uncertainties during decision-making supported by environmental performance information based on LCA. The key elements of this proposed approach include ‘distinguish ability analysis’, ‘principal components analysis’ and ‘multivariate statistical analysis’ to promote effective decision-making based on LCA environmental performance information. Bevilacqua et al. (2007) have presented a methodology for integrating design for environment (DFE) and LCA techniques both into new product development and into the process of re-designing a set of existing products. The proposed methodology benefits from the use of LCA data both during new product development and when modifying old products, with the aim of continuously reducing the overall environmental impact of products during their life cycle. Bovea and Wang (2007) have presented a novel re-design approach that allows the integration of environmental requirements into product development, taking into account cost and customer preferences. The proposed methodology allows the identification of environmental improvement options and the study of the effect that the incorporation of these options has over other traditional product requirements. Benedetto and Klemes (2009) have presented a novel approach to the environmental performance strategy map that complements environmental and financial considerations with the introduction of a new graphical representation.

Sakao (2009) has proposed the application of quality engineering in the early phase of environmentally conscious design (Ecodesign). The author has presented a framework for the classification of environmental characteristics of products/services in two dimensions. The integration of the the classification and the strategies is applied to three environmental characteristics against Japanese markets. Heijungs et al. (2010) have presented a framework that is able to incorporate different models for environmental analysis, with the option of a broader scope that also includes economic and social aspects, thus covering the three pillars of sustainability. This framework builds on the ISO framework for LCA, but takes a broader view, and allows to move from micro questions on specific product life styles up to macro questions in which the entire societal structure is part of the analysis. Jeswani et al. (2010) have presented the potential options for deepening and broadening the LCA methodologies beyond the current ISO framework for improved sustainability analysis. The authors have investigated several environmental, economic and social assessment methods, and suggested some options for integrating other methods for broadening and deepening the LCA.

3. Methodology

The methodology followed during this study is shown in Figure 1. As shown in Figure 1, the project starts with the review on ECQFD, LCA and sustainable product development. This is followed by the identification of tools/techniques for sustainable product development suggested in the literature. A suitable organisation for conducting case study has been identified. This is followed by the identification of environmental voice of customer (VOC) and environmental engineering metrics (EMs). This is followed by the application of ECQFD Phases I and II for an electric vehicle by deploying EM items into product components. The effect of a set of design changes on EM items and the effect of design changes on EM into environmental quality requirements are determined with the help of ECQFD Phases III and IV. This is followed by the LCA of individual components of an electric vehicle. Then the practical inferences are derived.

Figure 1 Methodology.

4. Case study

This section presents the details of the application of integrating ECQFD and LCA for an electric vehicle. As part of an ongoing research project on sustainable product design by the authors, an electric vehicle has been selected to demonstrate the applicability of the proposed method. The case study starts with the identification of a suitable electric vehicle manufacturing (EVM) organisation followed by the identification of VOCs and EMs. This is followed by the application of ECQFD on an electric vehicle in order to select the environmentally conscious design options from environmental perspective. This is followed by the application of LCA on an electric vehicle by developing a cost model, which considers EMs the of ECQFD as inputs. These EMs are selected as design options with the help of ECQFD. Hence LCA considers the outcome of ECQFD as a primary input to perform EMs lifetime assessment for its reusability with the help of the proposed cost model. The objective of this model is to provide industries with a simple indicator representing the potential reusability of a product that considers all necessary factors in the whole product's life cycle. The model incorporates the quality or technical aspect of products after the first lifetime and economic aspect of reuse strategy.

4.1 About the company

The case study was conducted in an EVM organisation located in India. EVM was established to manufacture environment-friendly and cost-effective electric vehicles.

4.2 Environmentally conscious quality function deployment

It is important to listen to CRs to obtain market needs and reflect them on the product design. QFD is a method to collect vaguely expressed quality requirements (VOC) from the market and deploy them to actual design work. QFD consists of two phases: Phases I and II. In Phase I, VOC items for a product are deployed to more detailed EMs to clarify their positions. In Phase II, the relationship between the above EM items and components of the product is clarified. Through these steps, the designer can identify which functions and components should be focused in order to satisfy CRs. The roles of QFD include the analysis between trade-off items for design and identification of their product's market competence through benchmarking processes.

This section describes the application of ECQFD and the kind of requirements and attributes that should be considered from the environmental point of view through a whole product life cycle, and integrates those environmental items into a set of feasible environmental VOC and EM, and their correlation factors. ECQFD consists of four phases. ECQFD Phases I and II are concerned with the identification of important parts of an electric vehicle that are vital for improving the environmental consciousness. ECQFD Phases III and IV are used to analyse which design changes among the formulated design options of an electric vehicle are most effective with regards to environmental improvement. Gathering and analysing the environmental VOCs are critically important in ECQFD in order to generate customer-oriented products. The environmental VOCs may come from a wide variety of sources such as surveys, focus groups, interviews, trade shows, complaints and even expert opinions. Later, environmental VOCs should be translated into EMs. To incorporate the environmental concerns in ECQFD, the voice of the customer consists of traditional and environmental customer needs.

A few important environmental VOCs considered for the case study of ECQFD are: easy to drive; fully automatic drive (no clutch and no gear); tubeless tyres; range of 80 km per charge; easy to charge at home or office; and disc brakes, with increased regenerative braking. When VOCs and environmental concerns are identified, a cross-functional team is needed to translate those needs into appropriate EMs. To better identify EMs, a systematic method, life cycle analysis, can be applied in the raw material, manufacturing, distribution, use and recycling stages. The important EM for the application of ECQFD includes high-torque AC induction motor; AC motor controller; 350 A microprocessor based with regenerative braking; microprocessor-based battery management system and power pack (lead acid batteries); and power train performance. As the EMs are considered in HOQ, the next step is to evaluate the relationship between each of both traditional and environmental VOCs and each of both traditional and EMs. Typically, the relationship is determined qualitatively, such as strong, medium, weak and no relation with appropriate weights by a cross-functional team on a scale of 1–5.

4.2.1 Identification of target for design improvement

This part of ECQFD describes Phases I and II of ECQFD for the application of ECQFD to the design of an electric vehicle. Table 1 illustrated the ECQFD Phase I, where the deployment of VOC to EM takes place. Each VOC is evaluated against each EM on a scale of 1–5. The total environmental score is then used to rank the VOC according to their environmental impact.

Table 1 ECQFD Phase I for an electric vehicle.

	EMs
VOCs	Customer weights	High-torque AC induction motor	AC motor controller	350 A microprocessor based with regenerative braking	Microprocessor-based battery management system	Power pack (lead acid batteries)	Power train performance
Easy to drive, fully automatic drive	5	5	5	5	3	3	5
Range of 80 km per charge	5	5	5		5	5	5
Easy to charge at home or office	5	5	3		5	5	1
Disc brakes, with increased regenerative braking	5	3	3	5	1		5
Tubeless tyres	3	5	3	5			1
Raw score		105	89	65	70	65	83
Relative weight		0.22	0.186	0.136	0.146	0.136	0.174

ECQFD Phase II is described as illustrated in Table 2, which is concerned with the deployment of EM items to product components. The relative importance of each product component is obtained in a similar manner as Phase I.

Table 2 ECQFD Phase II for an electric vehicle.

Engineering metrics	Phase I relative weight	AC motor	AC motor controller	Single reduction gear box	Battery pack	Battery charger	Energy management system	Energy absorbing bumper	Tubeless tyre
High-torque AC induction motor	0.220	5	5	3	1	3	1	3	3
AC motor controller	0.186	5	5	3	3	3	3	5	3
350 A microprocessor based with regenerative braking	0.136	3	5	5	3	3	5		5
Microprocessor-based battery management system	0.146	3	3	3	5	5	5
Power pack (lead acid batteries)	0.136	3	5	1	5	5	5	3	1
Power train performance	0.174	5	5	5	3	5	5	3	1
Raw score		4.154	4.698	3.342	3.118	3.906	3.738	2.52	2.208
Relative weight		0.183	0.207	0.147	0.137	0.172	0.164	0.111	0.097

The results of Phase II show that the important components are energy management system; AC motor; AC motor controller; battery charger; and energy management system.

4.2.2 Evaluation method of design improvement

When design engineers improve their product from the environment point of view, evaluating the effects of design changes on environmental aspects is an effective process after identifying the important components. In this section, methods to evaluate the effects of design changes for parts or components on environmental aspects are introduced in Phases III and IV of ECQFD. In Phase III, the effect of a set of design changes on EM items is estimated. There are two options for design engineers to decide their focus. Option I originates from target VOC. Option II is originated by examining the most important components identified in Phase II. Tables 3 and 4 show the examples of Phase III.

• Option I:

  	•	Microprocessor-based energy management system should be implemented in energy management system. Table 3 ECQFD Phase III of an electric vehicle for option I. Engineering metrics Phase I relative weight AC motor AC motor controller Single reduction gear box Battery pack Battery charger Energy management system Energy absorbing bumper Tubeless tyre Score Improvement rate of engineering metrics High-torque AC induction motor 0.220 0 0 AC motor controller 0.186 0 0 350 A microprocessor based with regenerative braking 0.136 5 5 0.172 Microprocessor-based battery management system 0.146 5 5 0.208 Power pack (lead acid batteries) 0.136 0 0 Power train performance 0.174 0 0 Table 4 ECQFD Phase III of an electric vehicle for option II. Engineering metrics Phase I relative weight AC motor AC motor controller Single reduction gear box Battery pack Battery charger Energy management system Energy absorbing bumper Tubeless tyre Score Improvement rate of engineering metrics High-torque AC induction motor 0.220 5 5 0.208 AC motor controller 0.186 0 0 350 A microprocessor based with regenerative braking 0.136 0 0 Microprocessor-based battery management system 0.146 0 0 Power pack (lead acid batteries) 0.136 0 0 Power train performance 0.174 5 5 0.156
  	•	Single reduction gear box should be incorporated with 350 A microprocessor with regenerative braking.

• Option II:

  	•	The AC motor controller should exhibit high rate of control to high-torque AC induction motor.
  	•	Performance of the power train should be improved in accordance with the operation of high-torque AC induction motor.

The objective of Phase IV is to translate the effect of design changes on EM into environmental quality requirements. Tables 5 and 6 show an example of Phase IV for an electric vehicle.

Table 5 ECQFD Phase IV of an electric vehicle for option I.

	EMs
VOCs	Customer weights	High-torque AC induction motor	AC motor controller	350 A microprocessor based with regenerative braking	Microprocessor-based battery management system	Power pack (lead acid batteries)	Power train performance	Improvement rate of CR	Improvement effect of CR
Easy to drive, fully automatic drive	5	5	5	5	3	3	5	0.011	0.057
Range of 80 km per charge	5	5	5		5	5	5	0.008	0.041
Easy to charge at home or office	5	5	3		5	5	1	0.010	0.054
Disc brakes, with increased regenerative braking	5	3	3	5	1		5	0.012	0.062
Tubeless tyres	3	5	3	5			1	0.020	0.061
Improvement rate of engineering metrics	0.00	0.00	0.00	0.172	0.208	0.00	0.00		0.275

Table 6 ECQFD Phase IV of an electric vehicle for option II.

	EMs
VOCs	Customer weights	High-torque AC induction motor	AC motor controller	350 A microprocessor based with regenerative braking	Microprocessor-based battery management system	Power pack (lead acid batteries)	Power train performance	Improvement rate of CR	Improvement effect of CR
Easy to drive, fully automatic drive	5	5	5	5	3	3	5	0.014	0.07
Range of 80 km per charge	5	5	5		5	5	5	0.014	0.07
Easy to charge at home or office	5	5	3		5	5	1	0.012	0.062
Disc brakes, with increased regenerative braking	5	3	3	5	1		5	0.016	0.082
Tubeless tyres	3	5	3	5			1	0.028	0.085
Improvement rate of engineering metrics	0.00	0.208	0.00	0.00	0.00	0.00	0.156		0.369

4.2.3 Evaluation of DFE options

The improvement effect for the VOCs with their weights was calculated for each design from environmental perspective through Phases III and IV. In this case study, the scores 0.275 and 0.369 are obtained for options I and II, respectively, and it has been concluded that option II is found to be the best.

4.3 Life cycle assessment

Life cycle assessment (LCA) is an environmental assessment of the life cycle of a product. An LCA looks at all aspects of a product's life cycle – from the first stages of harvesting and extracting raw materials from nature, to transforming and processing these raw materials into a product, to using the product and ultimately recycling it or disposing of it back into nature. LCA of an electric vehicle is necessary to evaluate the environmental impact of an electric vehicle over its life. LCA is the most successful tool to assess environmental considerations in the product design process. LCA is used for assessing the environmental impact of products and processes. An LCA should provide a level playing field based on a consistent methodology applied across all products and at all stages of their production, transport, use and disposal or recycling at end of life. ISO 14040 standards provide guidelines on the principles and conduct of LCA studies that provide an organisation with the information on how to reduce the overall environmental impact of its products and services. ISO 14040:2006 describes the principles and framework for LCA including the definition of the goal and scope of the LCA; the LCI analysis phase; the LCIA phase; the life cycle interpretation phase; reporting and critical review of LCA; limitations of LCA; the relationship between LCA phases; and conditions for use of value choices and optional elements.

Since the detailed assessment of LCA is time consuming, simplified LCA methodology proposed by Kaebernick et al. (2003) has been used in this study. The proposed simplified methodology in this case study is based on the principles of group technology, applied to a wide variety of industrial products by using both product characteristics and environmental performance indicators as clustering variables, to identify common environmental behaviour of product groups. This leads to grouping of products according to their environmental behaviour in the four phases of a product's life cycle, the material phase, the manufacturing phase, the usage phase and the disposal phase. In this context, a cost model has been developed, which considers EMs of ECQFD as a primary input to this proposed cost model of LCA. This integrates ECQFD and LCA by considering environmental requirements as equal associates to the traditional requirements of cost and quality which is explained in this section.

4.3.1 Assessment model for individual components

Traditionally, four key objectives have been used for decision-making in a design process, namely product performance, product cost, development cost and development speed. Today, in view of sustainable development, fifth objective, the environmental performance must be added. This generates a trade-off model for sustainable development, which can be used for balancing the five key design objectives against each other. The advantage of this approach is that the environmental requirements are fully integrated in the process, enjoying the same importance rating as all the traditional objectives. The new objective, the environmental performance, can be evaluated by applying LCA, which is explained in this section. As a result, the fundamental trade-off rules for sustainable development can be derived from the integration of ECQFD and LCA model, which considers environmental requirements as equal associates to the traditional requirements of cost and quality.

A cost model has been developed, integrating production and environmental costs as well as the technical status of an old part product for reuse. The objective of the model is to provide industries with a simple indicator representing the potential reusability of a product that considers all necessary factors in the whole product's life cycle. The model incorporates quality or technical aspect of products after the first lifetime and economic aspect of reuse strategy. The proposed model has been applied for assessing the reusability of each part and the electric vehicle as a whole. The calculations and the results for part assessment are listed in Table 7. For the model, three new parameters have been defined, namely product gain (PG), product value (PVL) and product life cycle cost (PLCC). The PG represents the monetary outcome from the sales of the product or component after deducting PLCC. The model calculates the PG as the difference between the PVL and the PLCC.

Table 7 Assessment model for an electric vehicle components.

Description	AC motor	AC motor controller	Single reduction gear box	Battery pack	Battery charger	Energy management system	Space frame	Dent proof ABS body panel	Energy absorbing bumper	Tubeless tyre
Producing a new component
Product cost	32,374	31,238	28,000	57,952	46,628	8580	18,400	28,000	8800	9600
Environmental cost	3237.4	3123.8	2800	5795.2	4662.8	858	1840	2800	880	960
PLCC	35611.4	34361.8	30,800	63747.2	51290.8	9438	20,240	30,800	9680	10,560
MP	40,467	39,047	35,000	72,440	37,302	10,725	23,000	35,000	11,000	12,000
PE (1 for reuse  potential and 0  for non-reuse potential)	1	1	0	1	0	1	1	1	1	1
PVL	40,467	39,047	0	72,440	0	10,725	23,000	35,000	11,000	12,000
	4855.6	4685.2	− 30,800	8692.8	− 37,302	1287	2760	4200	1320	1440
Remanufacturing a old component
Procurement cost	9635	9297	8333	17,248	8881.42	2554	5476.2	8333	2619	2857
Re-manufacturing cost	14,715	14,199	12,727	26,342	13,564	3900	8364	12,727	4000	4364
Environmental cost	147.2	142	127.3	263.42	135.64	39	83.64	127.3	40	43.64
PLCC	24497.2	23,638	22,333	43853.4	22,581	6493	13,924	22,333	6659	7264.64
MP	40,467	39,047	35,000	72,440	37,302	10,725	23,000	35,000	11,000	12,000
PE	1	1	0	1	0	1	1	1	1	1
PVL	40,467	39,047	0	72,440	0	10,725	23,000	35,000	11,000	12,000
	15,970	15,409	− 22,333	28586.6	− 22,581	4232	9076	12,667	4341	4735.36
	11114.4	10,724	8467	19,894	14,721	2495	6316	8467	3021	3295.4

The PVL represents the technical performance or quality status of the product, which can be measured by the product effectiveness (PE). Reliability is used as the basis for estimating the quality of a product or component. For a new product, reliability can be set to 100%, and this implies that PE = 1. PLCC includes product costs and environmental costs:

where MP is the market price in terms of Indian National Rupees.

Product reliability can decrease over time through the use of the product. Consequently, if a product is reused, its PE may be smaller than the PE of the new product. Basically, there are two components in PLCC, which are product cost (C _P) and environmental cost (C _E):

Also, the following assumptions were made for the calculations. Based on the sensitivity analysis, the environmental cost set as 10% of product cost and 1% of re-manufacturing cost was found to be realistic. Therefore, these figures are used to calculate the environmental cost for the new and old products, respectively. PE indicates whether a part has reuse potential or not. The PE is to be assessed on the usage conditions of the product.

5. Results and discussions

The introduction of environmental requirements into the product development process at all stages of a product's life enables sustainability in the product development process. The improvement effect of CR for option II of ECQFD process is more than that of option I. It reveals that ECQFD enables sustainability in the process of product development at EVM, since option II is formulated according to the outcomes of ECQFD Phase II. The comparison results for all components of PG and PLCC are shown in Figures 2 and 3. Figure 2 shows that all components of an electric vehicle have the positive values of ΔPG, which means they are feasible for reuse. If any component contains negative ΔPG, then these components are considered not feasible for re-manufacturing. Also Figure 3 shows that the difference between PLCC values for new and old components are too high, which also indicates that all components of an electric vehicle are potential for reuse and re-manufacturing. The integration of ECQFD and LCA reveals some re-design suggestions for more environmentally friendly products and systems.

Figure 2 Comparison of PG for old and new components of an electric vehicle.

Figure 3 Comparison of PLCC for new and old components of an electric vehicle.

In order to explore the feasibility of deploying the process of sustainable product development, a feedback session has been conducted at EVM. Five executives from the various department of EVM participated in the feedback session. The format of the questionnaire is shown in Figure 4. The consolidated responses of the executives are given in Table 8. Besides, the overall opinions of the executives are presented in Table 9. Based on the analysis of the responses of the executives, it has been found that integration of ECQFD and LCA at the stage of product development would enable the attainment of sustainability at EVM.

Figure 4 Format of questionnaire.

Table 8 Consolidated responses of the executives.

		Average response of the executives in a Likert's scale of range 1–10 (1, not at all possible; 5, partially possible; 10, completely possible)
Serial number	Question	E1	E2	E3	E4	E5	Average response
1	To what extent do you believe that the ECQFD would enable the attainment of sustainability in your organisation?	9	9	8	8	9	8
2	To what extent do you believe that the simplified LCA methodology is practically feasible and would enable sustainability in your organisation?	9	7	9	8	9	8
3	To what extent do you believe that the suggested product development cycle would enable sustainability in the process of designing product, process and services?	9	9	8	8	9	9

Table 9 Overall opinions of the executives.

Executive code	Response
E1	ECQFD and LCA integration is practically feasible in our organisation
E2	The method is useful for our organisation for enabling sustainability
E3	Suggested methodology indicates the feasibility of transforming traditional product development cycle into sustainable development cycle
E4	The tools like ECQFD and LCA consider environmental requirements as equal partners to the traditional requirements of cost and quality in our organisation
E5	The feasibility for reuse enables sustainability in the process of product development of our organisation

6. Conclusion

Environmental issues are gaining justifiable popularity among society, government and industry due to negative environmental developments. The introduction of environmental requirements into the product development process at all stages of a product's life enables the EVM to develop environmentally conscious electric vehicle. The manufacturing of environmentally friendly products is critical in order to minimise the use of virgin resources (Gungor and Gupta 1999). This can be achieved by studying the life cycle of the product from its design stage to its retirement stage and incorporating this information into engineering design and production. Integration of ECQFD and LCA enables the organisation to design environmentally conscious products. The design options generated by ECQFD also enable the organisation to design environmentally conscious products. The assessment model of LCA illustrates the consideration of environmental requirements as equal partners to the traditional requirements of cost and quality in an electric vehicle. The assessment model described in this study provides a useful tool to decide upon the potential of reuse of components at the end of their life. The analysis of the response of executives indicates that the integration of ECQFD and LCA for sustainable product development process would enable sustainability in the manufacturing organisations.

6.1 Scope for future research

The sustainable product design model integrated with ECQFD and LCA has been test implemented in a leading EVM organisation. Hence, the inferences derived from the conduct of the study are applicable to similar manufacturing organisations. Also we intend to introduce Fuzzy Eco-QFD method which is a tool to enable decision-making to determine the degree of importance for environmental VOC items in order to improve objectivity of the method. The current model only addresses the possibility of reusing old components for similar application in the future. Therefore, future research should attempt to incorporate technological advancements into the model. The environmental costs could be simulated along with other factors to provide a better understanding of the implementation of reuse.

Acknowledgement

The authors thankfully acknowledge the Department of Science and Technology (DST), New Delhi, India, for sanctioning the fund pertaining to the project titled ‘Development of a model for ensuring sustainable product design in automotive organizations’ under SERC Scheme (Ref: SR/S3/MERC-0102/2009) towards the conduct of the study reported in this paper.

Additional information

Notes on contributors

Gopinath Rathod

1

U. R. Madhyasta

2

Notes

1. Email: [email protected]

2. Email: [email protected]