On rank reversal and TOPSIS method

Rank reversal is a phenomenon that occurs when a decision maker, in the process of selecting an alternative from a set of choices, is confronted with new alternatives that were not thought about when the selection process was initiated. It depends on the relationship between this new alternative and the old ones under each criterion. In this paper, we study the rank reversal phenomenon in the TOPSIS method and we propose modifications in the algorithm of Hwang and Yoon in order to solve the problem. Moreover, we present a general demonstration of the proposed modifications in the algorithm, as well as a numerical example to show these modifications.