Group decision making based on multi-granular distribution linguistic assessments and power aggregation operators

In this paper, we focus on multi-attribute group decision making problems with multi-granular distribution linguistic assessments. First, the relationship between a linguistic 2-tuple and a distribution linguistic assessment is analyzed. Second, an approach for unifying multi-granular distribution linguistic assessments is proposed based on the extended linguistic hierarchies model. Third, from the relationship between a linguistic 2-tuple and a distribution linguistic assessment and the DAWA operator, a procedure which can represent the aggregated distribution linguistic assessment using initial linguistic term sets is also presented. Fourth, we develop some power aggregation operators, i.e. distribution linguistic power weighted averaging (DLPWA) operator and distribution linguistic power ordered weighted averaging (DLPOWA) operator to aggregate distribution linguistic assessments, which can relieve the influence of unfair assessments on the final aggregated results. Eventually, two novel approaches for group decision making with multi-granular distribution linguistic assessments are proposed before given a numerical example to illustrate the proposed approaches.