Green Supplier Selection with a new PROMETHHEE-Cloud Group Decision Making Method; Case Study: A Manufacturer of Oil Products

The spread of environmental pollution caused by factories producing petroleum products has led to the increasing attention of governments to the issue of green supply chain management in this category of industries. In this regard, the main goal of this research is to draw a group decision-making structure that addresses the issue of green supplier selection (GSS) in one of the largest refineries producing petroleum products in Iran. For this purpose, first after conducting detailed studies on the most used decision-making criteria, 8 criteria were selected for final decision-making including price, quality, transportation, energy consumption, environmental management system, green production, carbon emission and waste management. Then, after examining the various types of decision-making methods considering the existing research gap, a new method has been proposed that integrates the CLOUD model based on uncertain linguistic variable with the PROMETHEE method. The innovative CLOUD-PROMETHEE method was investigated in solving the problem of outsourcing paraffin production in this refinery factory and provided significant and useful results. The final results were successfully presented in the form of a preference graph, which provides a very suitable view for evaluating suppliers to company managers. The proposed model has been able to consider the advantages of PROMETHEE method including the possibility of combining quantitative and qualitative data, choosing preference functions, independent weighting and without normalization by solving decision-making uncertainties using the cloud model.