The multi-hour service system design problem

This paper studies the multi-hour service system design problem that involves locating service facilities, determining their number and capacities and assigning user nodes to those facilities under time varying demand conditions. The goal is to minimize total costs made of the costs of accessing facilities by users and waiting for service at these facilities as well as the cost of setting up and operating the facilities. A unified model is proposed for the problem to exploit the benefits of the non-coincidence of demand across busy-hours. Two Lagrangean relaxation-based heuristic solution procedures are developed and the results of extensive computational experiments are reported.