A fuzzy multi-criteria group decision making based on ranking interval type-2 fuzzy variables and an application to transportation mode selection problem

In this paper, we propose a fuzzy multi-criteria group decision-making method based on ranking interval type-2 fuzzy variables. First, we present a ranking method developed by relative preference index which we define using generalized credibility measure to rank interval type-2 fuzzy variables. Then, based on the proposed ranking method, we develop a new method to solve fuzzy multi-criteria group decision-making (FMCGDM) problems where linguistic ratings of the alternatives and the criteria weights are represented by interval type-2 fuzzy variables. The proposed FMCGDM method is applied to a transportation mode selection problem to find most preferable mode among available modes based on some selection criteria. The proposed method is simple in computation and important as it uses interval type-2 fuzzy variables which are more reasonable and sensible to represent linguistic terms rather than by type-1 fuzzy variables. A numerical experiment has been done to illustrate the proposed method.