The coordination index of fuzzy opinions under group decision-making

This paper regards a group decision-making process, where experts' opinions are expressed by interval fuzzy numbers. A concept of the coordination index of finite collection of interval fuzzy numbers is introduced. The implementation of the idea is based on the metric approach providing an easy procedure to determine the coordination degree of experts' opinions. Extended operations for inclusion, union and intersection of interval fuzzy numbers are introduced. A theoretical basis for this approach is established, showing that it is correct under a whole class of metrics on the set of interval fuzzy numbers. The practical examples of application of the introduced approach are given as well.