Modeling Heterogeneous Vehicle Routing Problem with Strict Time Schedule

Vehicle Routing Problem with time windows (VRPTW) is a well known combinatorial optimization problem normally to be used for obtaining the optimal set of routes used by a fleet of vehicles in logistic system. In VRPTW it is assumed that the fleet of vehicles are all homogeny. In this paper we consider a variant of the VRPTW in which the assumption of homogeny is dropped. Now the problem is called Heterogeneous VRP (HVRP). As the logistic company has so many customers, it puts a very strict restriction in time delivery for each vehicle used. Regarding to the structure of the problem we use integer programming approach to model the problem. A feasible neighbourhood method is developed to solve the model