Solving the p-Center problem with Tabu Search and Variable Neighborhood Search

The p-Center problem consists of locating p facilities and assigning clients to them in order to minimize the maximum distance between a client and the facility to which he or she is allocated. In this paper, we present a basic Variable Neighborhood Search and two Tabu Search heuristics for the p-Center problem without the triangle inequality. Both proposed methods use the 1-interchange (or vertex substitution) neighborhood structure. We show how this neighborhood can be used even more efficiently than for solving the p-Median problem. Multistart 1-interchange, Variable Neighborhood Search, Tabu Search, and a few early heuristics are compared on smalland large-scale test problems from the literature. © 2003 Wiley Periodicals, Inc.