Green supplier selection problem using TOPSIS extended by D numbers in tractor manufacturing industry

This research aims to evaluate the suppliers by a combined decision-making method with a new concept under uncertainty with D-number structure. Due to the importance of suppliers as a level of supply chain, determining factors for supplier selection decision is of key importance. Criteria in this study all are taken from the most recent articles so far. To consider the issue of environmental indicators related to this case can be considered sharp. In the existing evaluation methods, experts can propose their opinion under uncertainty only in one level. But in new proposed decision-making method, experts can proposed their idea about each alternative versus criteria in multi-level simultaneously. Therefore, in this method a group D-number structure with TOPSIS as a compromised decision making method to evaluate supplier selection has been applied. Finally to clearing the proposed method, the tractor company of Tabriz is studied as a case study. © Copyright 2019 Inderscience Enterprises Ltd.