Group Multi-criteria Decision Making Method with Triangular Type-2 Fuzzy Numbers

Type-2 fuzzy sets/numbers (T2FSs/T2FNs) attract more and more attention in fuzzy decision field. The existing studies mostly focus on the general properties of T2FS, or interval type-2 fuzzy number whose membership degrees are denoted by intervals. A new form of T2FN named triangular type-2 fuzzy number is proposed, whose primary and secondary memberships both have the continuous triangular feature. For aggregating the triangular type-2 fuzzy information, two operators are also defined. Based on them, a method is developed to handle the duplex linguistic group multi-criteria decision making problems and rank the alternatives. Finally, an example is provided to show the feasibility of the method.