A conceptual framework for a normative theory of "decision-aid"

The intent of this paper is to develop a conceptual framework for a normative theory of "decision-aid". Here the word normative does not apply to the decision-maker, for whom aid is provided, but to the scientist and to his work of analysis and modelling. This framework is appropriate to problems with multiple conflicting objectives. The traditional optimization on a fixed set of alternatives (mutually exclusive actions) is treated as a particular case. More generally, cases dealing with either fixed or evolutive sets of potential actions not necessarily pairwise incompatible are considered. Amongst others, the concept of a consistent family of criteria together with those of true-criterion, precriterion, semi-criterion, pseudo-criterion are introduced. Reasons for which multicriteria decision-aid may not fit in with the assessment of a unique true-criterion are briefly discussed. Several situations calling for a modelling of 'global preferences so as to "extract" good actions from a given set, otherwise than by optimizing a value function, are considered. Lastly, a new interactive procedure called "evolutive target procedure" leading to compromises, in the presence of n conflicting criteria and flexible constraints, is proposed.