anking Irregularities When Evaluating Alternatives by Using Some ELECTRE Methods

tract: ELECTRE II and III methods enjoy a wide acceptance in solving multi-criteria decision-making (MCDM) lems. Research results in this paper reveal that there are some compelling reasons to doubt the correctness of roposed rankings when the ELECTRE II and III methods are used. In a typical test we first used these ods to determine the best alternative for a given MCDM problem. Next we randomly replaced a optimal alternative by a worse one and repeated the calculations without changing any of the other data. Our utational tests revealed that sometimes the ELECTRE II and III methods might change the indication of the alternative. We treat such phenomena as rank reversals. Although such ranking irregularities are well known e additive variants of the AHP method, it is the very first time that they are reported to occur when the CTRE methods are used. These two methods are also evaluated in terms of two other ranking tests and they them as well. Two real-life cases are described to demonstrate the occurrence of rank reversals with the CTRE II and III methods. Based on the three test criteria presented in this paper, some computational riments on randomly generated decision problems were executed to test the performance of the ELECTRE d III methods and an examination of some real-life case studies are also discussed. The results of these inations show that the rates of the three types of ranking irregularities were rather significant in both the lated decision problems and the real-life cases studied in this paper.