Multiple Criteria Decision Making (MCDM): From Paradigm Lost to Paradigm Regained?*

Because trade-offs (Pareto optimal, non-dominated or efficient sets) are not properties of criteria or objectives, but of sets of feasible alternatives, the proper task of decision making is to work on designing proper sets of alternatives rather than assuming them to be fixed and given a priori. In fact, decision making takes place only when multiple criteria and trade-offs are present. All the rest (single criteria, aggregates or utilities) are simply analysis, measurement and search, not decision making. Similarly, optimization must involve design of the configuration or ‘shape’ of sets of alternatives because no given and fixed system can be optimized. Traditional ‘optimization’ is therefore measurement and search, or just computation. Anything given and fixed a priori cannot be optimized. Multiple criteria or objectives can never be conflicting per se because their properties emerge only when applied to different sets of alternatives. Criteria are only ‘measure tapes’ and no trade-offs can exist among them. Because decision making is incompatible with a single criterion, all decision making involves multiple criteria: thus, Multiple Criteria Decision Making (MCDM) becomes a redundant designation. These and similar insights and conclusions call for MCDM paradigm re-assessment: is it about decision making, or about analysis, measurement and search (explication) through computation? Eight different concepts of optimality are presented, as well as theories and models of trade-offs elimination, conflict dissolution, optimal system design, de novo programming, theory of the displaced ideal and other advances related to feasible set optimal re-design and re-configuration. Copyright# 2011 John Wiley & Sons, Ltd.