Random Time Location - Routing Problem

In logistics management decision systems, location allocation problems and vehicle routing problems are the two fields attract many concerns. The location of the distribution facilities and the routing of the vehicles from these facilities are interdependent. Location routing problems that combine LAP and VRP consider the interdependence of these two aspects together, so it realizes the optimization of the overall logistics distribution channel.This paper examines a generation of the location routing problems in which stochastic traveling time is considered. LRP with stochastic time differs from the well known LRP in that the actual traveling time is uncertain when the vehicle routes are designed, and it becomes much closer to actual logistics problems.As a NP-hard problem, most of the algorithms for LRP confine to two-phase algorithms or algorithms based on it. It is divided into LAP and VRP problems, and let the output of LAP to be the input of VRP. Obviously, such treatment fails to reflect the advantages of LRP that it considers LAP and VRP together. This paper regards LRP as a whole, and puts forward a one stage genetic algorithm dealing with LRP. The encoding, crossover, mutation methods and etc. are depicted at length in this paper. A computational study verifies this novel GA to be feasible and scientific.