Résumé en anglais

The objective of multiple criteria approaches is to help us to make better decisions, but what is the meaning of ‘better’? This field has developed considerably in the past twenty years. The development makes us fully aware of the limitations on objectivity encountered in the field of decision-aid and, consequently, of the virtual impossibility of providing a truly scientific foundation for an optimal decision. Work carried out under the rubric of mcdm (multiple criteria decision making) bases its claims to legitimacy on a framework in which these limitations are left aside. multiple criteria decision aid (mcda) must be seen from a different perspective. Its aim is, above all, to enable us to enhance the degree of conformity and coherence between the evolution of a decision-making process and the value systems and objectives of those involved in this process. The purpose of decision-aid is, therefore, to help us make our way in the presence of ambiguity, uncertainty and an abundance of bifurcations. We shall analyse multiple criteria concepts, models and procedures from both these viewpoints.