Let G=(V,E) be a connected directed graph expressing a distribution network. The elements of D⊆V represent demand centers, while S⊆V contains the candidate supply centers. To each node x∈S, the authors associate a weight w(x) which corresponds to the cost of installing a supply center at node x. To every arc (x,y)∈E they associate a weight a(x,y) which indicates the required time to reach node y directly from node x. The purpose of this paper is the determination of the subsets of S under a given budget restriction, so to minimize the longest delivery time of facilities to the demand nodes of D.
