COPEL Transmission Parana State Energy Company

Abstract:- Results of research into the use of fuzzy sets for multicriteria decision making are presented. Two classes of problems that need the application of a multicriteria approach are classified. According to this,>< MX , and>< RX , models may be constructed. Analysis of>< RX , models is considered as part of a general approach to solving a wide class of optimization problems with fuzzy coefficients. This approach consists in formulating and analyzing one and the same problem within the framework of interrelated models. It allows one to maximally cut off dominated alternatives. The subsequent contraction of the decision uncertainty region is based on reduction of the problem to multicriteria decision making in a fuzzy environment with applying two techniques based on fuzzy preference relations. The first technique (lexicographic procedure) consists in step by step comparison of alternatives, that provides the sequential contraction of the decision uncertainty region. The second technique is associated with constructing and analyzing membership functions of a subset of nondominated alternatives obtained as a result of simultaneous considering all criteria. The results of the paper are of a universal character and are already being used to solve problems of power engineering