A new Semi-Lagrangean Relaxation for the p-median problem

Recently Beltran-Royo et.al presented a Semi-Lagrangean relaxation for the classical p-median location problem. The results obtained using the Semi-Lagrangean relaxation approach were quite impressive. In this paper we use a reformulation of the p-median problem in order to start from a formulation more suitable for Semi-Lagrangean relaxation and analyse the new approach on examples from the OR library.