Outranking Methods for Multiple Criteria Group Decision Making Based on Interval Type-2 Fuzzy Sets

The theory of interval type-2 fuzzy sets provides an intuitive and computationally feasible way of addressing uncertain and ambiguous information in decision-making fields. Many studies have developed multiple criteria decision analysis methods in the context of interval type-2 fuzzy sets; most of these methods can be characterized as scoring or compromising models. Nevertheless, the extended versions of outranking methodologies have not been thoroughly investigated. The aim of this research project is to develop outranking models and methods for solving multiple criteria group decision-making problems within the interval type-2 fuzzy environment. Concerning the relative importance of multiple decision makers and group consensus of fuzzy opinions, this study constructs the collective decision matrix, which is based on interval type-2 trapezoidal fuzzy numbers, by using a hybrid average approach with weighted averaging operations and signed-distance-based ordered weighted averaging operations. Next, this study propounds several useful outranking methods, including the interval type-2 fuzzy LAM (Linear Assignment Method), QUALIFLEX (QUALItative FLEXible multiple criteria method), ELECTRE (ELimination Et Choice Translating REality), and PROMETHEE (Preference Ranking Organization METHod for Enrichment Evaluations) methods, for appropriately managing collective fuzzy data for inclusion in multiple criteria group decision analysis. The research period for this project is four years and the following main topics are addressed during each of the four years: (i) development of interval type-2 fuzzy LAM methods, (ii) development of interval type-2 fuzzy QUALIFLEX methods, (iii) development of interval type-2 fuzzy ELECTRE methods, and (iv) development of interval type-2 fuzzy PROMETHEE methods for multiple criteria group decision analysis. With regards to the first-year research, this study proposes an interval type-2 fuzzy LAM method for producing an optimal preference ranking of the alternatives, in accordance with a set of criterion-wise rankings and a set of criterion importance. This study also develops nonlinear assignment-based methods for managing imprecise and uncertain subjective ratings with incomplete preference structures. Concerning the second-year research, this study presents an interval type-2 fuzzy QUALIFLEX method for investigating all possible permutations of the alternatives with respect to the level of concordance of the complete preference order. An integrated nonlinear programming model is also established to estimate the criterion weights and the optimal ranking order of the alternatives with incomplete information. With regards to the third-year research, this study proposes an interval type-2 fuzzy ELECTRE method by employing a signed distance approach. In addition to the ELECTREcally non-dominated solutions, this study presents other methods that yield the linear ranking orders of the alternatives. Concerning the fourth-year research, this study establishes an interval type-2 fuzzy PROMETHEE method to rank alternative actions among (conflicting) criteria based on the signed distance approach. We provide the interval type-2 fuzzy PROMETHEE I for a partial ranking of the alternatives and the interval type-2 fuzzy PROMETHEE II for a complete ranking of the alternatives. The feasibility and applicability of the proposed methods are illustrated by real-world applications and computational experiments, and a comparative analysis with other outranking approaches is conducted to validate the effectiveness of the proposed methodologies.

Project ID:PB10301-0260
External Project ID:NSC102-2410-H182-013-MY3