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.