A Fuzzy Multicriteria Group Decision-Making Method with New Entropy of Interval-Valued Intuitionistic Fuzzy Sets

Anew entropymeasure of interval-valued intuitionistic fuzzy set (IVIFS) is proposed by using cotangent function, which overcomes several limitations in the existing methods for calculating entropy of IVIFS. The efficiency of the new entropy is demonstrated by comparing it with several classical entropies.Moreover, an entropy weightmodel is established to determine the entropy weights for fuzzy multicriteria group decision-making (FMCGDMs) problems, which depends on incomplete weight information of criteria in IVIFSs setting. Finally, an illustrative supplier selection problem is used to demonstrate the practicality and effectiveness of the proposed method. It is capable of the handling the FMCGDM problems with incomplete known weights for criteria.