Exploitation of a Rough Approximation of the Outranking Relation in Multicriteria Choice and Ranking

Given a finite set A of actions evaluated by a family of criteria, we consider a preferential information in the form of a pairwise comparison table (PCT) including pairs of actions from a subset B⊆A×A described by graded preference relations on particular criteria and a comprehensive outranking relation. Using the rough set approach to the analysis of the PCT, we obtain a rough approximation of the outranking relation by a graded dominance relation. Decision rules derived from this approximation are then applied to a set M⊆A of potential actions. As a result, we obtain a four-valued outranking relation on set M. The construction of a suitable exploitation procedure in order to obtain a recommendation for multicriteria choice and ranking is an open problem within this context. We propose an exploitation procedure that is the only one satisfying some desirable properties.