Electre-Score: A first outranking based method for scoring actions

In this paper, we present (to the best of our knowledge) the first outranking method to assign a score to each alternative. This method is part of the Electre family, and we will call it Electre-Score. In contrast to the Multi-Attribute Value Theory methods, Electre-Score does not construct a value function for each criterion to proceed then to the aggregation into a single value. Instead, Electre-Score makes use of the outranking relations to make a comparison with sets of reference actions (to which a score is assigned) and assigns a score range to each action and a representative score in the range to each action. This is a more robust way of proceeding given the fragility of a single score. The reference actions have similar nature and characteristics of limiting profiles in Electre Tri-nB and the reference scores are assigned to them through the application of the deck of cards technique. Because this method uses outranking relations, it makes also possible to take into account the imperfect knowledge of data and to avoid systematic compensatory effects. Some fundamental theoretical results guaranteeing the consistency of the method, an illustrative example and a case study in the domain of healthcare system evaluation are also provided in this paper.