An Outranking-Based Approach Modeling Satisfaction–Dissatisfaction Intensity, Preference Dependence, and Discordance Strength in Group Decision

There are numerous proposals for Group Decision-Making (GDM) inspired by the ELECTRE multiple criteria decision approach. These proposals capitalize on ELECTRE's resemblance to certain voting systems and its ability to navigate veto situations. However, while ELECTRE-based methods have commendable features for establishing the credibility degree of the predicate “x is collectively considered at least as good as y”, they do not address three relevant issues: (1) the reinforced preference in favor of x exhibited by certain members of the group; (2) the strength of the coalition of Decision-Makers (DMs) who favor y over x; and (3) the effects of preference dependence (complementarity, redundancy, antagonism) among different DMs. This paper addresses group ranking problems within scenarios where a group is under the control of a special powerful actor, called a “Supra-Decision Maker”, or when a group adheres to a predetermined system of rules agreed upon by its members. Unlike other ELECTRE-based methods for GDM, this proposal comprehensively addresses the issues (1), (2) and (3) to determine the credibility degree of the collective outranking predicate. This determination can be utilized to derive a collective ranking or another form of recommendation in GDM. This proposal is expected to excel in a collaborative organizational environment where group members express genuine judgments, devoid of malicious intentions to manipulate collective decisions. Moreover, it has relevance in socially oriented decision-making contexts, especially when government agencies seek to reconcile opinions of diverse stakeholder groups with highly contradictory points of view. In such scenarios, where phenomena such as preference dependence, reinforced preference, and intense disagreement manifest, this proposal could offer valuable insights.