A hybrid GRASP-tabu search metaheuristic for a Four-Layer Location-Routing Problem

Abstract

The location-routing problem simultaneously considers location, allocation, and vehicle routing decisions to design optimal distribution networks. In this paper, a hybrid GRASP-tabu search metaheuristic developed for a complex four-layer LRP is presented. The LRP integrates location, allocation, vehicle routing, and transshipment problems. The metaheuristic decomposes the problem into two sub-problems, a location-allocationtransshipment problem and a routing problem. Two metaheuristics of GRASP and tabu search are combined to solve the first sub-problem in which the routing cost is considered implicitly. The Clarke-Wright Savings algorithm and a node ejection chains algorithm are used to solve the second sub-problem.