A Hybrid Tabu Search for a Vehicle Routing Problem with Double Time Windows for the Depot and Multiple Use of Vehicles: Case of Fuel Delivery

We address in this paper a distribution real case problem facing the fuel supplying companies. The cost of acquiring vehicles is often more significant than the routing cost. The goal is to minimise the number of required vehicles. We deal with a vehicle routing problem with double time windows for the depot and multiple use of vehicles (VRPDM). There is a single depot with double time windows, the first window is for travelling and the second one (smaller) is for loading vehicles. The problem consists of designing and assigning routes to vehicles while considering time windows and capacity constraints. To solve this problem a hybrid tabu search based approach is proposed with a new heuristic for scheduling and assignment routes to vehicles. The computational results are reported for a set of 70 instances with 100 clients, and compared to those of evolutionary approach.