Group decision-making under uncertainty: FAHP using intuitionistic and hesitant fuzzy sets

The decision-making process can be described as dening the decision goals, gathering the related criteria and possible alternatives, evaluating the alternatives, and selecting an alternative or ranking the alternatives. Multicriteria decision-making (MCDM) methods are an important set of tools for addressing challenging decisions since they enable the decision maker to handle uncertainty, complexity, and conicting objectives. In MCDM, the predetermined alternatives are ranked according to the decision makers’ evaluation of multiple criteria. MCDM problems usually require both quantitative and qualitative factors to be evaluated. The main problem for qualitative criteria is that the values for such criteria are often imprecisely dened for the decision makers. In the evaluation of the qualitative criteria, the desired value and the weight of importance for the criteria are usually dened in linguistic terms. In crisp or conventional methods, it is difcult to express the character and signicance of criteria exactly or clearly (Chou et al., 2008). The conventional approaches tend to be less effective in dealing with the imprecision or vagueness of the linguistic assessment (Kahraman et al., 2003; Tolga et al., 2013; Kaya and Kahraman, 2011). Due to this reason, the use of fuzzy set theory in MCDM for evaluating various factors and alternatives seems more convenient by allowing decision makers to express their ideas more adequately (Zadeh, 1965; Beskese et al., 2004; Kulak et al., 2010).