Choosing the best objects by a set of the qualitative features

Abstract

It is generally accepted that the choice of the best technical solutions in the design of complex technical systems must be carried out on the basis of a multi-criteria approach. However, it is known that at the initial design stages, developers, as a rule, do not have exact values of basic technical indicators. Moreover, many (if not all) indicators are qualitative in nature, and the probability of making a non-optimal decision increases due to the uncertainty of the initial data. Therefore, it is advisable to try to restrict the choice domain, eliminating the deliberately “uncompetitive” objects. In the well-known ELECTRE method, for this purpose, some “preference” relation is introduced, indirectly determined by the choice of “weights” of particular quality indicators and threshold values of the so-called concordance and discordance indices. Unfortunately this approach is characterized by the lack of a clear operational sense of the weights and thresholds introduced, as well as the possible occurrence of oriented cycles in the preference relation graph. This makes it difficult to interpret the results of applying the procedure for excluding “worst” objects by the ELECTRE method. In this regard, the article proposes a new approach to the problem of choice domain restriction. On the set of the objects under consideration, some irreflexive and asymmetric dominance relation is constructed, allowing a solution according to von Neumann-Morgenstern, which simultaneously is also the so-called C-core. At the same time, the considered dominance relation – unlike the preference relation in the ELECTRE method already mentioned – has a clear “physical” meaning and does not require the introduction of any directly immeasurable parameters like “weights” and “thresholds,” which always question the adequacy of the model to actual decision maker’s preferences system.