Extension of TOPSIS for decision-making problems with interval data: Interval efficiency

There are some methods for solving Multiple Criteria Decision-Making problems, of which one if the TOPSIS method. When data is nondeterministic like interval data, the method must be modified to show the correct result. In this research we present a new TOPSIS method for ranking DMUs with interval data yielding the interval score for each alternative and in the end we show that when data is deterministic, our new method is the same as the conventional one. (C) 2008 Elsevier Ltd. All rights reserved.