Abstract
This study investigates the vehicle routes for a firm with its own delivery fleets and a single depot. A mathematical programming approach is employed to construct a vehicle routing model for handling mixed pickup and delivery operations by referring to the Vehicle Routing Problem with Pickup and Delivery (VRPPD). Furthermore, this study utilizes a heuristic algorithm to develop a problem-solving procedure. A revised Nearest Neighbor (NN) method is developed to obtain an initial solution. The 2-Opt exchange and Simulated Annealing (SA) method are adopted to develop the solution-improving procedure. Analytical results of this study are the optimal sequence of vehicle routes and the customer sets served by each vehicle. A sensitivity analysis among vehicle capacity, travel distance and number of routes is also proposed.