Vehicle Routing Problem with Stochastic Travel Times: Balancing Service and Transportation Costs
This paper studies a vehicle routing problem with soft time windows and stochastic travel times. A model is developed that considers both the transportation costs (total distance traveled, number of vehicles used and drivers' total expected overtime) and the service costs (early and late arrivals). We propose a Tabu Search method to solve our model. Different initial solutions are used to examine the trade-off between computation time and solution quality. An initialization algorithm is developed to construct feasible routes by taking into account the travel timestochasticity. Solutions provided by the Tabu Search algorithm are further improved by a post-optimizer method. We conduct our computational experiments for well-known problem instances. Results show that our Tabu Search method performs well by obtaining very good final solutions in a reasonable amount of time.
Tom Van Woensel is Associate Professor of Operations Management and Logistics at the Technische Universiteit Eindhoven in the Netherlands.
|Dr. Peter van Baalen|