Optimization of Delivery Considering Redelivery and Loading Methods

Delivering packages door-to-door is convenient because of its accuracy and speed. Recently, such delivery services have become widely used for online shopping. However, package delivery may sometimes fail to be completed in the specified time window because of the large number of packages. Therefore, it is important to optimize the delivery distance. This distance depends on the location of customers and whether they are absent. In this paper, we examine several cases of loading packages by considering redelivery, and evaluate delivery distance using the branch and bound method and the genetic algorithm. From the results, we conclude that the delivery distance depends on the probability of redelivery, and that the optimum order for visiting customers depends on their locations.