Methods of multicriteria decision making in fuzzy environment and their applications

Results of research into the use of fuzzy set theory for multicriteria decision making are presented. The application of a multicriteria approach is associated with the need to solve: 1) problems in which solution consequences cannot be estimated with a single criterion; 2) problems which can be solved on the basis of a single criterion, however their unique solutions are not achieved because the uncertainty of information produces decision uncertainty regions. In accordance with this, two classes of models are considered with using the Bellman-Zadeh approach and the technique of fuzzy preference relations, respectively, to their analysis. Advantages opened up by their application are discussed. The results are of a universal character, have found applications, and are illustrated by considering problems of power engineering.