Mahdi Zarghami - Faculty of Civil Engineering, University of Tabriz, Tabriz, ۵۱۶۶۴ Iran
Reza Ardakanian - Department of Civil Engineering, Sharif University of Technology, Tehran
Ferenc Szidarovszky - Systems and Industrial Engineering Department, University of Arizona, Tucson, AZ ۸۵۷۲۱-۰۰۲۰, USA.

All realistic multi criteria decision making (MCDM) problems face various kinds of uncertainty. One of these uncertain parameters is the optimism degree of the Decision Maker (DM), which has an important effect on the results. Fuzzy linguistic quantifiers will be used to obtain the values of this parameter and then, it will be assumed to have stochastic nature. A new approach will be introduced for the fuzzy-stochastic modeling of MCDM problems by merging the stochastic and fuzzy approaches into an improved OWA operator. The results of the new approach give the expected value and the variance of the combined goodness measure for each alternative. In order to combine these two characteristics a composite goodness measure will be introduced. The theoretical results will be illustrated in the Sefidrud watershed management problem. By using this measure more sensitive decisions are given to the stakeholders whose optimism degrees are different than that of the decision maker.

Multi criteria decision making; Watershed management; Ordered weighted averaging; Fuzzy linguistic quantifiers; Stochastic uncertainty;