  In this paper, a new method based on TOPSIS and optimization models is
proposed for multi-attribute group decision-making in the environment of
interval-valued intuitionistic fuzzy sets.Firstly, by minimizing the sum of
differences between individual evaluations and the overallconsistent
evaluations of all experts, a new optimization model is established for
determining expert weights. Secondly, based on TOPSIS method, the improved
closeness index for evaluating each alternative is obtained. Finally, the
attribute weight is determined by establishing an optimization model with the
goal of maximizing the closeness of each alternative, and it is brought into
the closeness index so that the alternatives can be ranked. Combining all these
together, the complete fuzzy multi-attribute group decision-making algorithm is
formulated, which can give full play to the advantages of subjective and
objective weighting methods. In the end, the feasibility and effectiveness of
the provided method are verified by a real case study.
