Negotiation model for group decision with ELECTRE TRI – the ELECTRE TRI-NG

Abstract

Since its conception ELECTRE TRI has been widely used to deal with several problems in the problematic of sorting. However, the inherent limitation of this method lies in its working with only one decision-maker. Currently there is an ELECTRE TRI version that can be used with multiple decision-makers, but it lacks the tools to deal with non-cooperative situations. Thus, this paper puts forward a negotiation procedure to be applied when using ELECTRE TRI. The procedure was inspired by the last-diminisher procedure and a version of the Nash Demand Game, Divide-the-Dollar, in order to establish an envy-free Nash Equilibrium and to control greed. The method establishes a negotiation process between decision-makers, in order to define each player's degree of participation in determining the values of the ELECTRE TRI criteria, weights and parameters. Each parameter is divided into negotiable shares that will be distributed by means of the negotiation procedure, which represents the degree of participation of the decision-maker's preferences.

ELECTRE ME: a proposal of an outranking modeling in situations with several evaluators

“…While dealing with group decision or evaluation situations in which the opinions or perceptions of several or multiple evaluators appears, there are two mains streams and basic approaches: the consensus and the voting systems. The consensus is reached through dialogue and, as reported in Sobral and Costa (2012), the first approach can produce good solutions, once it usually incites discussions and induces a better comprehension about the problem. Unfortunately, the dialogue and interactive-discussion-based approaches are limited to a small number of evaluators.…”