Identifying the Relative Importance of Implementation Strategies in Green Supply Chain Management (GSCM) Practices via Fuzzy Analytical Hierarchy Process (FAHP) Chia-Wei Hsua*, Allen H. Hub
a*
Institute of Engineering Technology, National Taipei University of Technology,1, Sec.3, Chung-Hsiao E. Rd., Taipei 10643, Taiwan, R.O.C. E-mail addresses:
[email protected] Tel.: 886-2-27712171 ext.4151 Fax: 886-2-27764702
b
Institute of Environmental Engineering & Management, National Taipei University of Technology,1, Sec.3, Chung-Hsiao E. Rd., Taipei 10643, Taiwan, R.O.C. E-mail addresses:
[email protected] Tel.: 886-2-27712171 ext.4151 Fax: 886-2-27764702
*
Corresponding author 1
Selection of priority approach for implementing green supply chain management (GSCM) practices in Taiwanese electronics industry: From Taiwanese perspective 格式化: 式化: 英文 (美國)
Abstract Green supply chain management (GSCM) has emerged and progressed as a proactive approach for improving environmental performance of processes and products in accordance with sustainable business, particular in electronics industry. This is because that European Union (EU) legislated for novel directives with WEEE, RoHS, and EuP. The concern of GSCM practice in electronics industry is how to select appropriate measures to greening supply chain for comply with the requirements of regulations and customer-firms. Although various studies have proposed a set of approaches for GSCM practices, yet no investigation has identified the reliability and validity of such strategies for electronics industry individually. Therefore, these approaches lacked consistency as 刪除: 刪除 s
a guide to assist companies in developing best GSCM practice. This study aims to
格式化: 式化: 字型: 非斜體
recognize and select appropriate strategy for implementing GSCM in Taiwanese
刪除: 刪除 proposes a structure model for strategy selection for implementing GSCM in Taiwanese electronic industry using the fuzzy analytic hierarchy process (FAHP). The model is developed using factor analysis to extract the strategies based on an extended literature review. Twenty strategies were identified via appropriate tests to determine their reliability and validity. The FAHP was then utilized to determine the relative importance of implementing the strategies. This
electronics industry. Based on an extended literature review, twenty approaches were identified via factor analysis to determine their reliability and validity and were extracted into four dimensions. And the fuzzy analytic hierarchy process (FAHP) was applied for determining relative importance and selecting appropriate approach in GSCM practice. The findings of this study demonstrated that ‘supplier management’ was the most important dimension, followed by ‘organization involvement’, ‘life cycle management’ and ‘product recycling’ from Taiwanese perspective. This result is
刪除: 刪除 study 刪除: 刪除 also demonstrates
contributive to how the model assists in making decisions when implementing GSCM practices. And the implications of GSCM practice in electronics industry are verified in 2
刪除: 刪除 Moreover 刪除: 刪除 , the 刪除: 刪除 s
this work help decision-makers identify those GSCM areas where acceptance and improvements can be made, and in prioritizing GSCM efforts.
Keywords: Green supply chain management; Strategy; Fuzzy analytic hierarchy process; Factor analysis 1.
Introduction
With the increase in environmental concerns during the past decade, a consensus is growing that environmental pollution issues accompanying industrial development should be addressed together with supply chain management, thereby contributing to green supply chain management (GSCM) (Sheu et al., 2005). Recently, the Waste Electrical and Electronic Equipment (WEEE), Restriction of Hazardous Substances (RoHS) and Eco-design for Energy using Products (EuP) directives passed by the European Union (EU) have prohibited use of hazardous substances and are responsible for products recycling in electronics manufacturing. With these legal changes that have directly impacted purchasing organizations, environment-related supplier initiatives have become essential to firm’s strategies (Cousins et al., 2004). Consequently, GSCM has become a necessary strategy for many companies in the electronics industry, including Dell, HP, IBM, Motorola, Sony, Panasonic, NEC, Fujitsu, and Toshiba (Zhu, and Sarkis, 2006). This phenomenon implies that company now recognizes that environmental awareness can be a source of competitive advantage (Walton et al., 1998). Due to the complexity of GSCM practices, customer and cost pressures, and regulation uncertainty, implementing GSCM is considered a thankless task that increases overall product cost. Therefore, the biggest challenge in GSCM practices for companies is to select suitable strategies in accordance with the regulations and customers requirements.
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The issue of GSCM is significant for Taiwan’s electronics industry as recent studies have shown that most of the world’s manufacturing will be relocated to Asia within the next two decades (US-AEP, 1999). Therefore, GSCM is an operational initiative many organizations, including those in Asia and South Asian region, are adopting to address such environmental issues (Rao and Holt, 2005). Taiwan is one of the most industrialized countries in the Asia-Pacific region. Most electrical and electronics manufacturers in Taiwan are involved in Original Equipment Manufacturing (OEM) and Original Design Manufacturing (ODM). These companies play important roles in global markets as their products have substantial market share. For example, the Taiwanese information industry has outpaced most of its international counterparts. At one time, Taiwan was the third largest producer of information products globally (Chen, 2004). Notably, in 2004, Taiwan was the leading provider of notebook PCs, liquid crystal display (LCD) monitors and chip foundry services achieving 72%, 68% and 70% market share, worth of $22 billion, $14 billion, and $8.9 billion, respectively (BusinessWeek, 2005). Nevertheless, these industries are subject to customer requests for green products and green manufacturing that comply with emerging environmental directives (such as WEEE, RoHS, and EuP). These directives, particular the RoHS, directly impact the electrical and electronic industries in Taiwan that export products to the EU—exports in 2004 exceeded US$7.8 billion. More than 3,000 companies were affected by the directives of EU. These directives also have far reaching influence on supply chain partners for multinational enterprises (Huang, 2005). In addition, China is developing its economy rapidly, while at the same time increasing its awareness of, and actions associated with, environmental protection (Zhu et al., 2006). Consequently, the Chinese government has instituted stringent environmental regulations (Wang et al.,
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2004), such as China’s RoHS and WEEE directives. These directives pose another significant pressure for Taiwanese electrical and electronic industries as most companies have moved their factories to China.
To date, GSCM remains a new management paradigm that lacks sound and comprehensive theory. Although numerous studies have proposed various schemes for implementing GSCM practices (Lamming and Hampson, 1996;
Lippmann, 1999;
US-AEP, 1999; Bowen et al., 2001; Yuang and Kielkiewicz-Yuang, 2001; Rao, 2002; Evans and Johnson, 2005; Zhu et al., 2005), no consensus exists regarding these schemes due to the uncertainty of regulations. For example, the RoHS directive lacks a standardized test procedure and an updated exemption annex of chemicals. These shortcomings result in significant problems when implementing GSCM. Currently, regulations lack consistent standards or practices for GSCM issues. Furthermore, increased
regulations—RoHS-EU,
RoHS-Korea,
and
RoHS-China—result
in
difficulties executing GSCM practices. Hence, enterprises cannot determine whether their executive strategies conform to regulations or ensure that current management approaches are working and have a low risk. Consequently, enterprises are at economic risk when choosing appropriate and strategies for GSCM practices.
The analytical hierarchy process (AHP) method, introduced by Saaty (1980), directs how to determine the priority of a set of alternatives and the relative importance of attributes in a multi-criteria decision-making (MCDM) problem (Saaty, 1980; Wei et al., 2005). The primary advantage of the AHP approach is the relative ease with which it handles multiple criteria and performs qualitative and quantitative data (Kahraman et al., 2004; Meade and Sarkis, 1998). However, AHP is frequently criticized for its inability
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to adequately accommodate the inherent uncertainty and imprecision associated with mapping decision-maker perceptions to extract number (Kwong and Bai, 2003; Chan and Kumar, 2007). It is therefore difficult to response to the preference of decision-makers by assigning precise numerical values. To improve the AHP method and recognize consistent strategies for implementing GSCM, this study applies the fuzzy analytic hierarchy process (FAHP) (Erensal et al., 2006) and uses triangular fuzzy numbers to express comparative judgments of decision-makers. A systematic approach of FAHP to identify priority strategies for GSCM implementation was adopted based on a complex and multi-criteria environment. As a result, the FAHP and its extensions are developed to resolve alternative selection and justification problems. The main goal of this study is to establish a consistent and prior strategy for implementing GSCM reliability and validity via factor analysis (FA). Applying the FAHP to conduct the relative importance of different strategies is extremely crucial, for the results can be used by managers implementing and adopting their own GSCM practices.
The remainder of this paper is organized as follows. Section 2 describes the GSCM and its practice in Taiwan. Section 3 discusses previous studies available in the area of the strategies for GSCM practices. Section 4 presents the proposed methodology for establishing a consistent framework for the FAHP model. Section 5 discusses the priority weightings for different strategies for implementing GSCM practices. Section 6 presents conclusion and future directions for research, particularly in reference to GSCM practices. 需要重新安排
Green supply chain management and its practices in Taiwan Currently, the lack of consensus regarding a definition for GSCM and GSCM practices is
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not surprising, as GSCM is the conflation of corporate environmental management and supply chain management, both of which are relatively new areas of study and practice (Zhu and Sarkis, 2004). Furthermore, different studies (Green et al., 1996; Narasimhan and Carter, 1998; Godfrey, 1998; Rao, 2002; Zhu and Sarkis, 2004) have defined GSCM from different perspectives, driving forces and purposes (Rao, 2002), implying that the definitions for GSCM and GSCM practices can be redefined for particular industries, goals, and properties. In this study, GSCM is defined as the management of raw materials, parts/components, processes, and services from suppliers to manufacturers to customers and product take back
with improvement to
environmental impacts though lifecycle stages. A number of strategies for implementing GSCM practice have been proposed. These strategies are aimed at mitigating the risks associated with supply chain interruptions or delays, and protecting a company’s reputation and brand image from damaging public controversies. van Hock (1999) also observed that GSCM has emerged as an important new archetype for achieving profit and market share by reducing environmental risk and impact and increasing ecological efficiency.
The original concept underlying the greening of supply chains in Taiwan was to implement a corporate synergy system (CSS) model as an innovative approach for promoting industrial waste minimization (IWM) among small and medium enterprises (SMEs) (Rao, 2002). The CSS is a management mechanism that encompasses formation of partnerships among firms in supply chains to attain specific objectives, and was adopted as the primary mechanism for promoting cleaner production (CP) that reduces the environmental impact from SMEs (Chiu et al., 1999). Currently, the Ministry of Economic Affairs (MOEA) has adopted the CSS model to introduce GSCM practices
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for central firms and their satellite manufacturing suppliers, which are mostly SMEs that have limited capital and manpower. The MOEA is thus promoting a Green Plan (GP) and forming an inter-governmental RoHS Service Group to assist Taiwanese industry in complying with EU regulations.
The GP, introduced at the end of 2004, includes three tasks: establish an information management system for green supply chains; develop a recycling system and management platform for green products; and, generate a certification database for green parts and components that conform to environmental requirements (MOEA, 2005). Additionally, the Taiwan Electrical and Electronic Manufacturers Association (TEEMA) have invited domestic certification and verification organizations, and equipment suppliers, large electronics companies and academic and research institutions to join the GP and assist industries in overcoming barriers to green technology. Another group, the MOEA’s RoHS Service Group, is a technology-oriented group coordinated by the Industrial Development Bureau (IDB) that provides diagnostic and guidance services, as well as technological consultation, education and training and an information service for Taiwanese electrical and electronics companies. To date, more than 1,480 companies have received guidance and assistance (MOEA, 2005). The RoHS Service Group and the Securities and Futures Bureau conducted general reviews of companies listed on the Taiwan Securities Exchange Corporation (TSEC)/GreTai Securities Market (GTSM) to determine how these companies and their suppliers responded to the RoHS directive.
格式化: 式化: 行距: 1.5 倍行高
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2.
Review and classification of green supply chain management practices
GSCM is progressing in electronics industry due to the EU passed the environmental regulations with WEEE, RoHS, and EuP. Those directives now are indistinct and incomplete so that consistent approach is inexistent. This has lead to
so that
manufacturers can not ensure their measures of implementing GSCM whether can comply with the requirements of directives. As a reason, GSCM practice in this study focus mainly on the concern of EU directives and how to adopt appropriate strategy for greening entire supply chain.
The WEEE directive aims to improve the environmental performance of electrical and electronic equipment (EEE) which requires the implementation of systems for take-back and treatment of electronic products (Directive, 2003). Currently the adoption of take-back is mainly divided into two methods. One can argued that collaboration on products recycling within the same industry sector. An example of IBM and Dell, as multinational enterprises, embraced reverse logistics by streamlining the manner in which they deploy old systems; and in the process make it easier for the customers to refurbish existing computers or buy new parts (Ferguson, 2000). Second is to join local recycling organization for achieving the recycling and recovery targets. Acer Corporation in Taiwan, a top laptop brand in Europe, has worked with several recycling systems in Europe, including Swiss Association for Information, Communications and Organization Technology (SWICO) in Switzerland, E1-Kretse in Sweden, El-Retur in Norway, Recupel in Belgium, Information & Communications Technology (ICT) Producer Cooperative in Finland, ICT Milieu in The Netherlands and Ecotrel in Luxemburg (Acer, 2005). Both take-back models for EEE can fulfill the requirements of WEEE directive but the selected difference is determined by firms in the volume of product recycling, capital and manpower investment, difference in recycling laws in each EU state. Additionally WEEE directive requires that company have to submit disassembly information to recycling disposal business while the products enter the market in one year. Therefore company unitized design for disassembly (DfD) concept to conduct disassembly report based on 3R (reuse, recycling, recovery) principle. This is because DfD is a powerful approach for improving the product’s end-of-life (EOL) ‘disassemblability’ by appropriate design of the product itself rather than improvement restricted to optimizing the disassembly processes and tasks for a given product (Viswanathan and Allada, 2006). 9
Viswanathan, S. and V. Allada, (2006), “Product configuration optimization for disassembly planning: A differential approach”, Omega 34, pp. 599 – 616. Directive 2002/96/EC of the European Parliament and of the Council of 27 January 2003 on Waste Electrical and Electronic Equipment (WEEE).
The EuP directive is the first directive requiring the incorporation of life-cycle-based environmental considerations into the product development process (Kautto, 2007). Several aims of EuP directive have stated: to ensure the free movement of energy-using products within the EU, to improve the overall environmental performance of these products and thereby protect the environment, to contribute to the security of energy supply and enhance the competitiveness of the EU economy and to preserve the interests of both industry and consumers (Commission, 2003). Various issues of controversy during the preparation process have been debated among NGOs, industry and its associations, and governments with respect to how to achieve ‘conformity assessment’. Kautto (2007) pointed out that Eco-Management and Audit Scheme (EMAS) and ISO 14000 based systems were accepted as ‘conformity assessment’, but the final proposal for EuP states that ‘it is not obligatory to make a life cycle analysis (LCA) according to relevant international standards’. Presently in practice manufacturers attempted to utilize LCA to perform the ecological profile with the inventory of environmental database for products. This is because that manufacturer shall perform an assessment of the environmental impact of a product throughout its lifecycle EuP directive required. From EuP directive, Kautto, P. (2007), “Industry–Government Interaction in the Preparation of a New Directive: Nokia, Industry Associations and EuP”, European Environment, 17, pp.79-91. Commission of the European Communities. 2003a. Proposal for a Directive of the European Parliament and of the Council on Establishing a Framework for the Setting of Eco-Design Requirements for Energy-Using Products and Amending Council Directive 92/42/EEC, COM (2003) 453 final. http://europa.eu.int/eur-lex/en/com/pdf/2003/com2003_0453en01.pdf [28 February 2007].
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說明目前歐盟三大指令衍生之問題與做法，說明目前整個實務做法的內容 A number of strategies for implementing GSCM practice have been proposed. These strategies are aimed at mitigating the risks associated with green supply chain interruptions or delays, and protecting a company’s reputation and brand image from damaging public controversies. Strategies for GSCM practices have been identified by various authors; they are briefly outlined below and summarized as Table I. ***Insert Table 1***
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Table I. Strategy for green supply chain management (GSCM) implementation in response to EU directive emphasized by selected authors
ctors iers meeting onmental auditing for suppliers iers environmental questionnaire liance statement ct testing report f material (BOM) lishing environmental requirements for asing items purchasing borative R&D with suppliers mation system g local recycling organizations boration on products recycling with the same industry ce disassembly manuals design onmental education and training management support onmental policy for GSCM -function integration ower involvement ive communication platform within anies and with suppliers lish a environmental risk management system SCM ier evaluation and selection ing the development of directives ying LCA to carry out eco-report lish an environmental database of products
Representative reference Lippmann, 1999; Yuang and Kielkiewicz–Yuang, 2001; Rao (2002) Lippmann, 1999, US-AEP, 1999; Yuang and Kielkiewicz–Yuang, 2001; Zhu et al., 2005 Lamming and Hampson, 1996; US-AEP, 1999; Bowen et al., 2001; Rao, 2002; Evans and Johnson, 2005 Yuang and Kielkiewicz–Yuang, 2001; Evans and Johnson, 2005 Evans and Johnson, 2005 Evans and Johnson, 2005 Lamming and Hampson, 1996; Lippmann, 1999; US-AEP, 1999; Yuang and Kielkiewicz–Yuang, 2001; and Johnson, 2005 Yuang and Kielkiewicz–Yuang, 2001; Rao, 2002; Zhu et al., 2005 Lamming and Hampson, 1996; Lippmann, 1999, US-AEP, 1999; Bowen et al., 2001; Rao, 2002 Yuang and Kielkiewicz–Yuang, 2001; Evans and Johnson, 2005 US-AEP, 1999; Bowen et al., 2001; Rao, 2002 Yuang and Kielkiewicz–Yuang, 2001 Lamming and Hampson, 1996; Rao, 2002 US-AEP, 1999; Yuang and Kielkiewicz–Yuang, 2001; Rao, 2002 Lippmann, 1999; Yuang and Kielkiewicz–Yuang, 2001 Lippmann, 1999; US-AEP, 1999; Evans and Johnson, 2005 Lamming and Hampson, 1996; Lippmann, 1999; US-AEP, 1999; Yuang and Kielkiewicz–Yuang, 2001 Lippmann, 1999; US-AEP, 1999; Yuang and Kielkiewicz–Yuang, 2001; Evans and Johnson, 2005 Rao, 2002 Lippmann, 1999 Bowen et al., 2001 Lamming and Hampson, 1996; Yuang and Kielkiewicz–Yuang, 2001; Rao, 2002 US-AEP, 1999 Lamming and Hampson, 1996; US-AEP, 1999; Rao, 2002 Lamming and Hampson, 1996
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Lamming and Hampson (1996) explored the concepts of environmentally-sound management (e.g. life cycle analysis, waste management, product stewardship, and so on), and linked them to supply chain management practices such as vendor assessment, lean supply, collaborative supply strategies, establishing environmental purchasing policy and working with suppliers to enable improvements.
Lippmann (1999) proposed various critical elements for the successful implementation of supply chain environmental management. Those components include the production of written GSCM policies, supplier meetings, training, collaborative R&D, top-level leadership, cross-functional integration, effective communication within companies and with suppliers, effective processes for targeting, evaluating, selecting and working with suppliers, and restructuring relationships with suppliers and customers.
US-AEP (1999) improved understanding of industry approaches to supply chain environmental management (SCEM) by focusing on seven major electronics firms. Some of the common SCEM tools employed by these firms are summarized as follows: (1) Prequalification of suppliers (2) Environmental requirements during the purchasing phase (3) Supply base environmental performance management (4) Building environmental considerations into product design (5) Cooperating with suppliers to deal with end-of-pipe consumer environmental issues (6) Reverse logistics (7) Influencing legislation to facilitate better SCEM policies (8) Working with industry peers to standardize requirements (for suppliers and purchasing items)
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(9) Informing suppliers of corporate environmental concerns (10) Promoting the exchange of information and ideas.
Bowen et al. (2001) conducted an exploratory analysis of implementing patterns and inductively derived three main types of green supply. The first type, greening the supply process, represents adaptations to supplier management activities, including collaboration with suppliers to eliminate packaging and recycling initiatives. The second type, product-based green supply, attempts to manage the byproducts of supplied inputs such as packing. The third type, advanced green supply, includes more proactive measures such as the use of environmental criteria in risk-sharing, evaluation of buyer performance and joint clean technology programs with suppliers.
Yuang and Kielkiewicz-Yuang (2001) presented an overview of current practices in managing sustainability issues in supply networks. Cross-functional teams, consisting of sales, environmental personnel, purchasing personnel, and personnel from other relevant departments, can be found in organizations with the most advanced strategies for sharing sustainability-oriented information. Organizations make available to their customers/suppliers their sustainability purchasing policy, goals and future targets via open days. Moreover, organizations have specific criteria as well as recognized standards (ISO14001), technical (lead-free soldering) and performance specifications that its suppliers must meet to be recognized as preferred suppliers. Additionally, supplier performances can be enhanced through on-site third-party auditing or periodic self-assessment by suppliers. Through collaboration with suppliers, training is not only administered to companies that supply advice on sustainability issues in purchasing, but is also delivered to suppliers to provide them with information on product life cycle.
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Rao (2002) argued that GSCM practices should include working collaboratively with suppliers on green product designs, holding awareness seminars, helping suppliers establish their own environmental programs, and so on. To green the supply chain, from the perspective of practitioners, companies have to integrate the ideas of green purchasing total quality management, in terms of employee empowerment, customer focus, continuous improvement and zero waste; life cycle analysis; and environmental marketing. Green purchasing comprises a number of environmentally-based initiatives, including a supplier environmental questionnaire, supplier environmental audit and assessments, environmental criteria for designating approved suppliers, requiring suppliers to undertake independent environmental certification, jointly developing cleaner technology/processes with suppliers, engaging suppliers in eco-design, and product/process innovation.
Evans and Johnson (2005) suggested that manufacturers should install documented and auditable systems to prevent noncompliant products from entering the EU. The installation of such systems would involve three steps. The first step is to determine the legal exposure of the company to EU Directives, and senior management must support this initial exposure assessment. The next step is to assign the task to a corporate-wide compliance team, due to the complex requirements of the RoHS Directive. The third step is to develop a corporate compliance statement, which should include a date for compliance and might also outline supplier requirements (i.e., testing, documentation, and so on). Through assessing the supply chain exposure to the EU Directives, companies can establish the material declaration process. However, companies should also qualify suppliers to determine their level of RoHS preparedness via questionnaires.
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Zhu et al. (2005) described a number of GSCM practices implemented by Chinese enterprises to improve their performance. Internal environmental management is a key to improving enterprise performance in terms of senior manager commitment and cross-functional cooperation. Commitment of senior managers is extremely conducive to the implementing and adoption stages for GSCM, because without such upper management commitment most programs are bound to fail. All GSCM practices are integrative and require cross-functional cooperation rather than simply being oriented to a single function or department. They suggested that green purchasing and eco-design are two emerging approaches and companies should focus on the inbound or early portions of the product supply chain. Currently, large customers have exerted pressure on their suppliers to achieve better environmental performance, resulting in greater motivation for suppliers to cooperate with customers for environmental objectives.
3.
Fuzzy analytical hierarchy process
The FAHP was applied to determine weight for the four dimensions and 20 sub-items for implementing GSCM practices, and provided the priority of those strategies for enterprise to adopt and adjust their current GSCM practices. Some calculation steps are essential and explained as follows: Step 1: Establishing the hierarchical structure Construct the hierarchical structure with decision elements, decision-makers are requested to make pair-wise comparisons between decision alternatives and criteria using a nine-point scale. All matrices are developed and all pair-wises comparisons are obtained from each n decision-maker. Step 2: Calculating the consistency
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To ensure that the priority of elements is consistent, the maximum eigenvector or relative weights and λmax is calculated. Then, compute the consistency index (CI) for each matrix order n using Eq. (1). Based on the CI and random index (RI), the consistency ratio (CR) is calculated using Eq. (2). The CI and CR are defined as follows (Saaty, 1980):
C.I . =
λmax − n
n −1 C .I . C.R. = R.I .
(1) (2)
where n is the number of items being compared in the matrix,
λmax is the largest eigenvalue, and RI is a random consistency index obtained from a large number of simulation runs and varies upon the order of matrix (see Table 2).
Step 3: Construct a fuzzy positive matrix A decision-maker transforms the score of pair-wise comparison into linguistic variables via the positive triangular fuzzy number (PTFN). The fuzzy positive reciprocal matrix can be defined as (Buckly, 1985)
[ ]
~ ~ k A k = Aij
(3)
where ~ A k : a fuzzy position reciprocal matrix of decision-maker k, ~k Aij : relative importance between i and j of decision elements ~k Aij = 1, ∀i = j ,
~k k Aij = 1 Aij ,
∀i, j = 1,2,....., n
Step 4: Calculate fuzzy weights value 17
According to the Lambda-Max method proposed by Csutora and Buckley (2001), the fuzzy weights of the hierarchy can be calculated. This process is described as follows.
[ ]
~ Let α=1 to obtain the positive matrix of decision-maker Amk = aijm
nxn
. Then,
apply the AHP to calculate weight matrix Wmk .
[ ]
k Wmk = wim , i = 1, 2, ......., n
(4)
Let α=0 to obtain the lower bound and upper bound of the positive matrix of
[ ]
~ decision-maker, Alk = aijl
nxn
[ ]
~ and Auk = aiju
nxn
. Then, apply the AHP to
calculate the weight matrix, Wl k and Wuk .
[ ]
(5)
[ ]
( 6)
Wl k = wilk , i = 1, 2, ......., n Wuk = wiuk , i = 1, 2, ......., n
To ensure the fuzziness of weight, two constants, S lk and S uk , are calculated as follows:
wk S lk = min imk 1 ≤ i ≤ n wil
(7 )
wk S uk = min imk 1 ≤ i ≤ n wiu
(8)
*
*
The lower bound ( Wl k ) and upper bound ( Wuk ) of the weight matrix are defined as
[ ] = [w ],
Wl k = wilk , wilk = S lk wilk , i = 1, 2, ........, n *
Wuk
*
*
k* iu
*
wiuk = S uk wiuk , i = 1, 2, ........, n *
*
*
(9) (10 )
*
Aggregating Wl k , Wmk and Wuk , the fuzzy weight for decision-maker k can be acquired as follows:
(
)
* * ~ k* Wi k = wilk , wim , wiuk , i = 1, 2, .........., n
(11)
Applying the geometric average to incorporate the opinions of decision-makers 18
is defined as follows:
(
~ ~ ~ ~ Wi = 1 Wi1 ⊗ Wi 2 ⊗ ......... ⊗ Wi n k
)
(12)
where ~ Wi : the fuzzy weight of decision-makers i is incorporated with K decision-makers.
~ Wi k : the fuzzy weight of decision element i of k decision-maker. k: number of decision-makers.
4.
Results and data analysis
5.1. Constructing the hierarchy of strategy of GSCM practices This study focused on sampling the perceptions and experience of GSCM-based companies in the Taiwanese electrical and electronics industries. Through a thorough and detailed analysis of the pertinent literature, a tentative list of 25 strategies of GSCM was developed and used as the basis for questionnaire development.
Data collection involved distributing questionnaires to various companies involved in semiconductors and optoelectronics, communication and networks, electronics and household appliances, and computers. Target respondents were selected from among the members of Taiwan Electrical and Electronics Manufacturers Association (TEEMA). Questionnaires were addressed to both the managing directors of the quality assurance and purchasing departments of the target organizations. This was done because most of the sample companies may lack green supply chain management representatives or departments. A total of 300 questionnaires were mailed out and 87 were returned, of which 84 were valid, representing a response rate of 28 percent (Table 4). According to the study on development and validation of critical factors and environmental
19
management, its response rate is 21.9 percent (Wee and Quazi, 2005). Furthermore, Antony et al. (2002) also pointed out that their research got 16.5 percent, which was normal and reasonable. This implies that the response rate of this study is acceptable, and it reflects the virtue of novel issue of GSCM practice.
Factor analysis in this study was applied to extract the strategy for implementing GSCM, which is based on the Eigenvalues are greater than 1. The deletion margin for analyzing the factor loading in this study was 0.6, because of the considered high if the load is above 0.6 (Kline, 1997). In this investigation, there are five items were eliminated after factor analysis because they had loadings of less than 0.6. Consequently, the remaining 20 items (Var. 2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24 and 25) were re-analyzed to extract 4 dimensions using the factor analysis, which denominated supplier management, product recycling, organization involvement, and life cycle management (Table 5).
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***Insert Table 5*** Table 5 Factor analysis results Dimension
Supplier management
Product recycling
Organization involvement
Life cycle management
Item 1. 2. 3. 4. 5. 6. 7. 1. 2. 3. 1. 2. 3. 4. 5. 6. 7. 8. 1. 2.
Environmental auditing for suppliers Supplier environmental questionnaire Compliance statement Product testing report Bill of material (BOM) Establishing environmental requirements for purchasing items Green purchasing Joining local recycling organization Collaboration on products recycling with the same sector industry Produce disassembly manual Green design Top management support Environmental policy for GSCM Cross-function integration Manpower involvement Effective communication platform within companies and with suppliers Establish a environmental risk management system for GSCM Supplier evaluation and selection Applying LCA to carry out eco-report Establish an environmental database of products
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Item loading range 0.657 0.722 0.828 0.842 0.619 0.747 0.830 0.886 0.931 0.613 0.624 0.618 0.658 0.750 0.769 0.677 0.727 0.639 0.830 0.829
Eigenvalues
Cumulative percentage
Cronbach’s alpha
12.504
50.02
0.9289
2.605
60.44
0.8338
1.325
65.74
0.9367
1.032
69.87
0.9156
Reliability test
The new Cronbach’s alpha values, ranging from 0.8338 to 0.9367, following the five items were dropped. Generally, Cronbach’s alpha value exceeding 0.7 is considered to have high internal consistency of scale (Lin et al., 2002). All the Cronbach’s alpha values in this study are greater than 0.7, revealing the high internal consistency and validity of our scales and demonstrating that all strategies have strong and relatively high reliability scores.
Content validity
The content validity of the questionnaire in this work is based on an exhaustive literature review and detailed evaluations by three senior quality assurance and product assurance practitioners. Consequently, we are confident that the critical strategies constructed by the factor analysis have content validity.
Construct validity
Factor analysis of this study was applied to assess construct validity. Bartlett’s test of sphericity and the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy were employed first to test the appropriateness of the data for factor analysis (Kaiser, 1974; Bagozzi and Yi, 1988). The test results of KMO show that the compared value is 0.863, significantly exceeding the suggested minimum standard of 0.5 required for conducting factor analysis (Hair et al., 1995). The Bartlett’s test of sphericity in this study demonstrated high value for all the four dimensions (p
