A group decision-making aggregation process

Within the frame of decision aid literature, decision making problems with multiple sources of information have drawn the attention of researchers from a wide spectrum of disciplines. In decision situations with multiple individuals, each one has his own knowledge of the decision problem alternatives. The use of information assessed in different domains is not a seldom situation. This non-homogeneous information can be represented by values belonging to domains with different nature as linguistic, numerical and interval valued or can be values assessed in label sets with different granularity and multigranular linguistic information. Decision processes for solving these problems are composed by two steps: aggregation and exploitation. The main problem to deal with non-homogeneous contexts is the aggregation manner of the information assessed in these contexts. The purpose of this paper is to address this problem and establish a procedure to aggregate individual opinions into a common decision to deal with non-homogeneous contexts. This process combines at the same time numerical, interval valued and linguistic information. Since subjectivity, vagueness and imprecision enter into the assessments of experts, the 2-tuple fuzzy linguistic representation model is used to deal with the fuzziness of human judgment.