Decisionmaking in the presence of fuzziness and uncertainty

The concept of fuzzy sets is being increasingly utilized to deal with illdefined terms and variables. Mathods have been proposed to find the optimal alternative in presence of fuzzy variables. In this paper a method for finding the optimal alternative in the presence of both, the fuzziness and the uncertainty, is presented. This method deals with those situations in which the ratings of the alternatives are known imprecisely and the state of the system is known with uncertainty. The impreciseness of the ratings is represented using fuzzy sets and the expected fuzzy rating for each alternative is calculated. The existing methods for finding the optimal alternative on the basis of the fuzzy ratings may then be employed for finding the optimal alternative from the expected ratings. This method is extended to those situations in which the optimal alternative is to be determined on the basis of more than one aspects having varying amount, known imprecisely, of importance.