Project Delivery System Decision Making using Pythagorean Fuzzy TOPSIS

The selection of project delivery systems is a complex decision-making process, which is also a critical task for owners. The complexity problem arises from the uncertainty of decision making environment and construction project itself. Pythagorean fuzzy sets (PFS), as an extension from intuitionistic fuzzy sets (IFSs) to deal with uncertainty information, has attracted more scholars’ attention in the decision making area. In this paper, we develop three similarity measures (i.e., 1-type PFSs similarity measure, 2-type PFSs weighted similarity measure, 3-type PFSs weighted similarity measure), and investigate their properties. Then an improved TOPSIS decision making framework is further established with PFSs information, in which the proposed similarity measures are employed to measure the similarity degree between each alternative and negative ideal solution and positive ideal solution. Finally, a case study of the selection of project delivery systems is presented to proof the performance of the proposed decision making method.