A distance-based collective weak ordering

A group decision-making approach can be seen as a two stage process. The fi rst stage allows for multi-cirteria evaluation of the alternatives and the second aims at deriving a collective weak ordering from the partial orderin gs supplied by the members after the first stage. The problem of combining the weak orderings to form a collective ranking is investigated. An axiomat ic structure relating to the concept of distance between binary relations i s developed. An algorithm for deriving the collective weak ordering is prop osed, based on the idea of ranking first the least dominated alternatives.