A modified grey-based decision-making approach to the supplier selection problem for the automobile industry

KGROUND AND OBJECTIVESIn the manufacturing sector, selecting the most suitable supplier is a critical strategic decision. In today's context, where sustainability has become a key performance indicator, the automotive industry emphasises supplier selection strategies that align with traditional economic criteria, as well as environmental and social sustainability. Sustainable supplier selection is a complex decision-making process. The objective of this article is to simplify the selection of a supplier, considering all three sustainability factors as important through the expertise of experts.METHODS: In this study, a grey-based decision-making approach is employed. To address ambiguity and capture subjective judgments effectively, a linguistic scale-based questionnaire is utilized for both supplier evaluation and criteria weight determination. The model converts the expert rating into a grey number-based rating for the criteria weight and the supplier performance rating on each of the identified criteria. The proposed method computes the relative closeness index. The evaluated relative closeness index ranks the best suppliers that are closest to the ideal positive supplier. To demonstrate the applicability and effectiveness of the proposed methodology, a case study from the automotive industry is presented.FINDINGS: The proposed method employs grey numbers to evaluate the criteria weights and grey numbers for supplier rating. Using modified grey relational analysis, the suppliers are ranked. The criteria identified by the experts were both quantitative and qualitative. The best sustainable supplier is supplier ۴, with the relative closeness index farthest from the possibility degree ۰.۵, with a value of ۰.۷۶۲۲. A comparative analysis was conducted, revealing that the top three ranked suppliers demonstrated consistent positions across the evaluated methodsCONCLUSION: Suppliers from the automobile sector were evaluated using distinct criteria. Industry experts prioritized traditional operational factors such as technical capability, product quality, delivery reliability, workplace safety, and employee health. Furthermore, environmental performance and sustainability were also rated favourably, highlighting the growing importance of environmentally sustainable practices. The study emphasizes the reduction in computational complexity associated with making informed decisions in complex scenarios.

کلیدواژه ها:

automobile industry ، modified Grey Relational Analysis ، multi-criteria decision making ، Sustainability ، Supplier Selection