Fuzzy Sets and Their Extensions: Literature Review on Fuzzy Extensions of AHP

The Analytic Hierarchy Process (AHP) has been extensively utilized in multi-criteria decision making. Fuzzy sets have been widely employed to extend it under vagueness and impreciseness. Recent extensions of ordinary fuzzy sets such as intuitionistic fuzzy sets, picture fuzzy sets, Pythagorean fuzzy sets, spherical fuzzy sets and neutrosophic sets have been employed to obtain the new versions of AHP under uncertainty. This chapter offers a concise overview of the literature on the integration of AHP with the extensions of ordinary fuzzy sets.