Raul Moragues (Operations Research Center, University Miguel Hernández of Elche), Juan Aparicio (Operations Research Center, University Miguel Hernández of Elche) and Miriam Steve (Operations Research Center, University Miguel Hernández of Elche)
Abstract:
In this paper, different upgrading strategies are investigated in the context of the
p-center problem. The possibility of upgrading a set of connections to different centers is considered as well as the possibility of upgrading entire centers, i.e., all connections made to them. Two variants for these perspectives are analyzed: in the first, there is a limit on the number of connections or centers that can be upgraded; in the second, an existing budget is assumed for the same purpose. Different mixed-integer linear programming models are introduced for those problems as well as data-driven lower and upper bounds. In most cases, an optimal solution can be obtained within an acceptable computing time using an off-the-shelf solver. Nevertheless, this is not the case for one particular family of problems. This motivated the development of a math-heuristic seeking high-quality feasible solutions in that specific case. Extensive computational experiments are reported highlighting the relevance of upgrading connections or centers in the context of the
p-center problem.