Gülşen Akman

Evaluating suppliers to include green supplier development programs via fuzzy c-means and VIKOR methods

Main focus of the study is to select suppliers being involved in green supplier development programs.Two-step supplier evaluation was applied via fuzzy c-means clustering.Supplier were evaluated via performance criteria and green criteria.After performance and green evaluation, VIKOR method is used to sequence suppliers.An illustrative example was provided in an automobile company. Green supplier development has became necessity as organizations increasingly compete on environmental supply chain capabilities. This paper aims to determine green/environmental performance of supplier, and define which suppliers need to improve their conditions about environmental issues, and identify which suppliers should be included to green supplier development programs to enhance their environmental performance. Therefore, primarily, performance criteria and green supplier evaluation criteria were determined via a survey, then factor analysis was conducted to evaluate validity of factors. Then two step clustering was performed by using c-means clustering method. In the first step of clustering, all suppliers of a firm performing in automobile industry were clustered according to criteria-delivery, quality, cost and service. Thus best performing suppliers were determined. In the second step of clustering, best performing suppliers determined in the first step of clustering were evaluated with environmental/green criteria. As a result of clustering, best performing suppliers were splitted to three groups according to green criteria-good, medium, poor. Lastly, suppliers within the poor group were sequenced by using VIKOR method in order to include green supplier development programs.

Evaluating Green Performance of Suppliers via Analytic Network Process and TOPSIS

Developments in environmental issues in the last few years have been forcing manufacturing companies to improve their environmental performances. Many firms developed integrated relationships with their suppliers to increase their environmental performance and to decrease their hazardous effects on the environment. Then, selecting suitable and green suppliers in the supply chain has become a key strategic consideration. A performance evaluation system for green suppliers is necessary to determine the suitability of suppliers to cooperate with the firm. Therefore, in this study, a model for evaluating green performance of suppliers is proposed, and a hybrid multicriteria decision making model is developed in order to evaluate green performance of the suppliers. The analytical network process technique is applied to handle the relationships and dependence of selection criteria and subcriteria and determine weights of the criteria. The technique for order preference by similarity to ideal solution is used to sequence the suppliers for ideal solution of the suppliers’ green performance evaluation problem. After a comprehensive literature survey, evaluation criteria of green performance for suppliers are determined. Finally, green performance of 18 suppliers of an automobile company was evaluated by this model. These 18 suppliers manufacture chassis and its components.

Logistics Service Provider Selection through an Integrated Fuzzy Multicriteria Decision Making Approach

Nowadays, the demand of third-party logistics provider becomes an increasingly important issue for companies to improve their customer service and to decrease logistics costs. This paper presents an integrated fuzzy approach for the evaluation and selection of 3rd party logistics service providers. This method consists of two techniques: (1) use fuzzy analytic hierarchy process to identify weights of evaluation criteria; (2) apply fuzzy technique for order preference by similarity to ideal solution (TOPSIS) method to evaluate and sequence alternatives and to make the final selection. Finally, an actual industrial application is performed in logistics department of a tire manufacturing company. For this, first, eight logistics supplier selection criteria were determined, and then the best alternative among seven logistics service provider companies was selected by the proposed method.

Fuzzy multi criteria decision making approach to innovative strategies based on Miles and Snow typology

Innovation which utilizes both competitive and co-operative relationships can be defined as the improvement of some new products, services or systems. Generation of an innovation strategy is an essential challenge in today’s competitive business world. Innovation provides a sustainable competitive advantage when the related activities become an indispensable element of the management within the company. In line with this issue, after a comprehensive literature review, five characteristic parameters of innovation are selected to analyze a company’s innovation strategy. The determined parameters are the strategic orientation of a firm, the abilities of a firm, the cultural structure, the attributes of products, and the environment of competition. The data belonging to the leading companies of their sector are evaluated by using these parameters and with the help of Fuzzy Analytic Hierarchy Process. Based on both the conceptual and empirical research, organizations are classified according to the Miles & Snow typology.

A TOOL FOR PRODUCT DEVELOPMENT PERFORMANCE MONITORING (PDPM) FOR ALIGNMENT WITH COMPETITIVE PRIORITIES

Product Development Process (PDP) has been recognized as a source of competitive profits, and thus, it has received increasing attention. The existing methods for monitoring PDP performance, however, are either cumbersome or fail to connect the competitive priorities to the performance management process. Accordingly, in this paper, a model to evaluate PDP performance is considered as a multi-criteria decision-making problem; and a solution method, based on DEMATEL and ANP, is proposed. The evaluation criteria set was developed using the concept of competitive priorities, and the overall model was applied to an actual data set from a group of machine manufacturers in Turkey. The use scenarios for the model are also discussed.

Fuzzy adaptive resonance theory approach to supplier involvement in product development: a case study in Turkish automobile industry

This study proposes a mechanism to evaluate suppliers for involvement during product development process. The proposed methodology is discussed within a multinational automobile firm and preliminary analysis indicates that the approach provides an effective mechanism for selecting suppliers involved in the product development process. To remedy to supplier integration problems, a clustering approach – fuzzy adaptive resonance theory (Fuzzy ART) – is used. The proposed methodology is explained using a case study that is realised in an automobile firm. Eventually, the results are presented comparatively, which obtained by current supplier evaluation system of the firm and provided from Fuzzy ART methodology. [Submitted 14 July 2009; Revised 16 November 2009; Accepted 17 November 2009]

Customer Needs Based Product Family Sizing Design: The Viper Case Study

This study explores the issue of optimizing the size of a product family as well as designing the product variants of the family in the context of designing a stand for a unique electric violin known as the “Viper.” The study uses collected customer data in order to identify the optimal number of design variants in the product family, generate design alternatives, assign each design to the appropriate customer type, and verify the outcome. The methodology begins with data collection through a survey of Viper players which is analyzed using K-means clustering analysis and segmentation in order to determine the optimal number of variants in the product family. This analysis also defines each customer group and each group’s specific customer requirements. Quality function deployment (QFD) is used to fit design concepts (generated by the requirements and specifications) to synthesized design variants and assign to a customer group. Then, analytic network process (ANP) is used to substantiate the outcome of the study by further verifying each Product Family Member-Customer Group mapping as well as the number of variants. This is achieved by simultaneously fitting the generated design concepts to customer requirements and customer groups through ANP. The ultimate goal of this work is to provide a simple, easy to understand, easy to reproduce, and customizable method for making product family size and design decisions in any industry.