Fuzzy Group Decision Making Model Based on Credibility Theory and Gray Relative Degree

In this paper, the problems of fuzzy multi-attribute group decision making in which the attribute values are given in the form of linguistic fuzzy numbers are studied. First of all, a new method called fuzzy dominance is given for ranking trapezoidal fuzzy numbers based on the credibility theory. Then the TOWA operator is presented to aggregate the trapezoidal fuzzy numbers. Furthermore, a new model is presented for the problems of fuzzy multi-attribute group decision making via TOWA operator, fuzzy dominance method and gray relative degree. Finally, a decision-making example is given to demonstrate the feasibility and rationality of this new model.