MpUFLP: Universal facility location problem in the p-th power of metric space

Abstract

We propose and study the MpUFLP (universal facility location problem in the p-th power of metric space) in this paper, where the universal facility location problem (UFLP) extends several classical facility location problems like the uncapacitated facility location, hard-capacitated facility location, soft-capacitated facility location, incremental-cost facility location, concave-cost facility location, etc. In UFLP, a set of facilities, a set of clients, as well as the distances between them are given. Each facility has its specific cost function w.r.t. the amount of clients assigned to that facility. The goal is to assign the clients to facilities such that the sum of facility cost and service cost is minimized. In traditional facility location problems, the unit service cost is proportional to the distance between the client and its assigned facility and thus metric. However, in our work, this assumption is removed and a generalized version of universal facility location problem is proposed, which is the so-called MnUFLP. When p=2, it is also known as l22 measure considered by Jain and Vazirani [J. ACM'01] and Fernandes et al. [Math. Program.'15]. Particularly in this case, we extend their work to include the aforementioned variants of facility location and a local search based (11.18+ε)-approximation algorithm is proposed. Furthermore, the reanalysis of the proposed algorithm gives a p-related performance guarantee for general p.