Optimization-based group decision making using interval-valued intuitionistic fuzzy preference relations

In this paper, we propose an optimization-based group decision making (GDM) method using interval-valued intuitionistic fuzzy preference relations (IVIFPRs). First, the concept of consistency of intuitionistic fuzzy preference relations (IFPRs) is provided. Moreover, the consistency index for IFPRs is presented. Subsequently, by splitting an IVIFPR into two IFPRs, an additive consistency is proposed for IVIFPRs. Afterward, a consensus index is presented for GDM. When the consistency and the consensus do not achieve the requirement, we propose several models to reach the requirement. Furthermore, individual IVIFPRs are integrated into a collective IVIFPR. After that, a procedure is offered to obtain the interval-valued intuitionistic fuzzy (IVIF) priority weights of the alternatives. Moreover, a new GDM method with IVIFPRs is offered. Finally, some application examples are offered. The proposed GDM method can conquer the shortcomings of the existing GDM methods. It offers us a useful way for GDM in the IVIF context. (c) 2020 Elsevier Inc. All rights reserved.