A method for aggregation of trapezoidal fuzzy estimates under group decision-making

This paper introduces a simple method for group decision-making, where experts' opinions are expressed by trapezoidal fuzzy numbers. The method is based on the metric approach providing an easy procedure for achieving a one-valued consensus. A new approach for determining experts' degrees of importance is proposed. A theoretical basis is established, showing that the method is correct under the whole class of metrics on the set of trapezoidal fuzzy numbers. A specific fuzzy aggregation operator is constructed for the realization of the proposed approach. It is shown that despite its simplicity the proposed method preserves such important properties as Agreement Preservation, Order Independence, Linearity property etc. A comparative appraisal of the results obtained by the proposed approach and some other methods is given as well.