A TWO-STAGE HYBRID META-HEURISTIC FOR PICKUP AND DELIVERY VEHICLE ROUTING PROBLEM WITH TIME WINDOWS

A two-stage hybrid meta-heuristic for pickup and delivery vehicle routing problem with time windows and multiple vehicles is considered in this paper. The first stage uses simulated annealing algorithm to decrease the number of used vehicles, the second stage uses tabu search to decrease the total travel cost. Experimental results show the effectiveness of the algorithm which has produced many new best solutions on problems within 600 customers. In particular, it has improved 45% and 81.7% of the best solutions on the 200 and 600-customer benchmarks, sometimes by as much as 3 vehicles. These results further confirm the benefits of two-stage approaches in vehicle routing problems.