A general type-2 fuzzy logic based approach for Multi-Criteria Group Decision Making

Decision making could be viewed to include Multi-Criteria Group Decision Making (MCGDM). MCGDM is a decision tool which it is able to find a unique agreement from number of decision makers/users by evaluating the uncertain judgment among them. Several fuzzy logic based approaches have been employed in MCGDM to handle the linguistic uncertainties and hesitancy. However, there is a need to handle the high level of uncertainties that exist in decision making problems involving numbers of decision makers/experts/users with varying points of view. In this paper, we present a general type-2 fuzzy logic based approach for MCGDM. The proposed system aims to handle the high levels of uncertainties which exist due to the varying Decision Makers´ (DMs) judgments and the vagueness of the appraisal. The proposed method utilizes general type-2 fuzzy sets. The aggregation operation in the proposed method aggregates the various DMs opinions which allow handling the disagreements of DMs´ opinions into a unique approval. We will present results from the proposed system deployment for the assessment of the postgraduate study. The proposed system was able to model the variation in the group decision making process exhibited by the various decision makers´ opinions. In addition, the proposed system showed agreement between the proposed method and the real decision outputs from DMs (as quantified by the Pearson Correlation) which outperformed the MCGDM systems based on type-1 fuzzy sets, interval type-2 fuzzy sets and interval type-2 fuzzy sets with hesitation index.