Multicriteria network location problems with sum objectives

In this paper network location problems with several objectives are discussed, where every single objective is a classical median objective function. We will look at the problem of nding Pareto optimal locations and lexicographically optimal locations. It is shown that for Pareto optimal locations in undirected networks no node dominance result can be shown. Structural results as well as eecient algorithms for these multi-criteria problems are developed. In the special case of a tree network a generalization of Goldman's dominance algorithm for nding Pareto locations is presented.