Location-Relocation of Mobile Facilities on a Stochastic Network

In this paper we deal with networks whose link travel times are not constant but undergo random changes. As a result of these changes the network may be in a finite number of discrete states. The paper contains a heuristic that finds the optimal set of locations for a set a facilities (servers), which may be moved, at a cost, in response to changes in the state of the network. The heuristic is suitable for a general number of facilities (previous research dealt with a single facility). The heuristic, which executes in polynomial time, is compared to the exact solution of the integer linear programming version of the problem for a series of small examples. For larger examples, the solution of the heuristic is compared to several bounds. An efficient method for performing sensitivity analysis is also indicated.