Hesitant Fuzzy Linguistic Group DEMATEL Method with Multi-granular Evaluation Scales

Decision-making trial and evaluation laboratory is a widely applied method used in the research of complicated socioeconomic system issues. However, this traditional method is not feasible when experts are non-homogeneous and hesitant between two or more statements. In this paper, hesitant fuzzy linguistic term sets (HFLTSs) are applied to facilitate the experts' expressions with regard to a direct influence level between factors, in order to analyze the causal relationship of the relevant system. Experts can use a linguistic expression (which is close to human expression) to show their opinions, which can be easily transferred into HFLTSs. Meanwhile, by using the concept of regarding the influence between factors as object and the level of influence as criteria, this paper proposes a comparison-based ranking algorithm to cope with the aggregation process of multi-granular scaled evaluation. In the algorithm, two adjustable possibility thresholds are introduced to control the output granule of the group consensus direct-influence scores. The validity and effectiveness of the proposed approach are finally demonstrated through an illustrative example and analysis.