MODIFIED ANT COLONY ALGORITHM FOR THE VEHICLE ROUTING PROBLEM WITH TIME WINDOWS

Vehicle Routing Problem with Time Windows (VRPTW) is an NP-Complete Optimization Problem. Even finding an optimal solution for small size problems is too hard and time-consuming. The objective of VRPTW is to use a fleet of vehicles with specific capacity to serve a number of customers with dissimilar demands and time window constraints at minimum cost, without violating the capacity and time window constraints. This problem has been solved with a number of heuristic and meta-heuristic solution algorithms and optimal or near optimal solutions gained. In this paper, a modified Ant Colony algorithm is proposed. In this algorithm we tried to simplify the solution procedure and computational complexities of ant colony metaheuristic. To gain this capability, we sacrificed some computational accuracy. Testing the solution procedure on the Solomon test-problems showed that this algorithm is capable of generating relatively good solutions.