A novel interval type-2 fuzzy evaluation model based group decision analysis for green supplier selection problems: A case study of battery industry

Selecting the most suitable supplier regarding to the environmental competencies is one of the main issues for companies and organizations. To address the issue, the group decision-making methodologies are well known approaches which could help decision makers (DMs) for evaluating the green supplier selection problems. In this study, a new model based on group decision-making approach is introduced under novel compromise ranking method and interval type-2 fuzzy sets (IT2FSs) for the green supplier selection problems. In the proposed approach, the assessment criteria are provided by DMs based on linguistic terms which are converted to interval type-2 fuzzy elements. In this respect, decision makers' weights are computed based on an extended interval type-2 fuzzy TOPSIS method considering the priority experts' opinions about the relative significance of criteria, and also a new ranking index is presented respecting to interval type-2 fuzzy Hamming distance measure to ranking potential alternatives. Hence, a real case study is considered to indicate the applicability of the proposed approach. In addition, results from the proposed approach are compared with the existing method in literature in order to illustrate the validation of proposed model. Furthermore, a sensitivity analysis is prepared to identify and determine the effects of different DMs' weights on ranking results. Results show that the proposed approach is an effective and practical decision tool for green supplier selection problems in fuzzy environment.