Multi- Objective Mathematical Model for Green Supplier Selection (Case Study: Supply Chain of IRAN KHODRO Company)

In the past few decades, due to negative environmental and social impacts of companies, there has been more pressure from the government and non-governmental organizations on companies to observe these issues in their operations, including their supply chain operations. To achieve an environment-friendly supply chain, the role of suppliers as the initial point of the supply chain is very crucial. So in addition to traditional criteria for evaluating and selecting suppliers such as price, delivery, and quality, it is essential to use new criteria, that while encompassing environmental issues, are fit to the characteristics of the industry under study. In this study, taking into account a set of economic and environmental criteria, a multi-objective integer mathematical programming model is proposed for solving the green supplier selection and order allocation problem under the multi-product, multi-sourcing, and single period assumptions. The case of this study is part of the IRAN KHODRO supply chain and focuses on the supplier selection and order allocation processes for 31 components of four types of the final products provided by 45 suppliers. The proposed mathematical model for the supply chain under study has 507 constraints and 449 decision variables. Then proposed model is solved via the ε–constraint method and Total Value of Green Purchasing (TVGP) is calculated. Results of the solution and sensitive analysis of the proposed model demonstrate that with increasing the importance of environmental issues in the supply chain, TVGP will increases.