DYNAMIC LOCATION-ROUTING PROBLEMS

Dynamic location-routing problems involve the determination of the least cost sequence of depot, vehicle fleet and route configurations in a distribution system over a given planning horizon. This paper presents two solution approaches to such problems. The first is an exact method appropriate for small scale problems. This method represents the problem by a suitable network and determines the optimum solution to an integer linear program associated with the network. In the second approach, some of the system costs are approximated and a global solution is then obtained by determining a shortest path on a directed graph. Under some hypotheses, this approach is suitable for large scale problems. The approximation scheme is illustrated with a simple example. (a)