ELECTRE-II method for group decision-making in Pythagorean fuzzy environment

This article develops a group decision support scheme that extends the widely accepted ELECTRE-II model to the Pythagorean fuzzy (PF) context. ELECTRE-II takes into consideration subjective human opinions, and establishes two types of embedded outranking relations which yield a complete preference ordering of actions. Its variants under different models have produced a considerable number of applications. Keeping in view the stronger capability of PF model to handle uncertain information, a group decision support algorithm, named as PF-ELECTRE-II is presented for opinions in the adaptable PF structure. A first phase aggregates the PF opinions of the experts on each alternative and criteria with the aid of suitable PF aggregation operators. Then, the algorithm introduces three types of PF outranking sets (concordance, indifferent and discordance sets), and establishes strong and weak outranking relations. The later are graphically represented by strong and weak outranking graphs, which are finally explored by a systematic iterative procedure that leads to the provision of a preferred system. We display these steps conducive to the PF-ELECTRE-II algorithm by a flow chart to facilitate its application. Finally, the decision results provided by this methodology in a supplier selection context are compared with those that available techniques put forward. A detailed comparative analysis is performed to establish the superiority of the proposed method.