Upgrading arcs to p-median problem in a bi-network

Résumé

We analyze the upgrading of arcs in the p-median problem on a binetwork. Both travel times and transportation costs are associated witheach arc. Our goal consists of simultaneously finding p medians, allocating each node to the median of minimum travel time and distributinga known budget among the arcs of the network to reduce their transportation cost, in order to minimize the total transportation cost of thesystem. We formulate it in two different ways as an integer programming problem, derive some properties of any optimal solution, developvalid inequalities and present computational results.