Spherical fuzzy extension of DEMATEL (SF‐DEMATEL)

In recent years, many versions of fuzzy sets are introduced in the literature. Spherical fuzzy sets (SFSs) concept is one of these latest developments. An SFS is a synthesis of Pythagorean fuzzy set (PFS) and neutrosophic set for providing a larger preference domain for experts and allowing them to express their hesitancy more comprehensively. The distinctive feature of SFSs is that the squared sum of membership, nonmembership, and hesitancy degrees is between 0 and 1 while each degree should be independently defined in [0,1]. The application of SFS on decision-making field may be about describing expert evaluations more informatively and explicitly. In this study, spherical fuzzy version of DEMATEL, one of the most cited multiple criteria decision-making approach, is introduced for considering the hesitancy degrees of experts when they evaluate the potential influences among the criteria. Another contribution made is the fuzzification of all the steps in DEMATEL until the last ones since the existing propositions in literature perform early defuzzification operations. The defuzzification is here applied as close to the end as possible for keeping the whole process fuzzy. The applicability of the proposition is shown in an illustrative example of a building contractor evaluation problem, and its robustness is shown by comparing the results with PFS-based and neutrosophic DEMATEL versions.