An integrated approach for assessing criterion importance with interval type-2 fuzzy sets and signed distances

Considering the decision-maker's point of view and circumstances in the multiple criteria decision-making process, subjective judgments of criterion importance are inherently imprecise and involve many uncertainties. Interval type-2 fuzzy sets are associated with greater imprecision and more ambiguities than type-1 fuzzy sets. In the context of interval type-2 trapezoidal fuzzy numbers, this article presents an integrated approach to combine the objective and subjective importances of decision criteria. In addition, the concept of signed distances has been extended to develop a new method for acquiring objective importance values of criteria with interval type-2 fuzzy data. Finally, the feasibility of the proposed methods is illustrated by a practical example of landfill site selection.