Solving the Hub Location-Routing Problem for National Postal Network with an Integrative Approach

The postal network is a network in which the flow of shipments is collected by vehicles from several sources and transferred to hubs; In the last step, the parcels are sent to the final destination by the vehicles. In order to provide this service, the hubs are located to process the parcels and the local routes are planned to pick up and delivery the packages in the hubs. This problem is known as location-routing problem. The current research seeks to locate the hub and the routing of freight carriers on an intercity scale and at the level of Iran. For this purpose, first, the mathematical model of the problem of locating the hubs and routing the cargo carriers is presented, and since the problem of locating-routing is in the category of complex problems with large dimensions, meta-heuristic algorithms have been used to solve it. In previous studies, meta-heuristic algorithms or a combination of them have been used to solve the location-routing problem, but in the study, the location-routing problem has been solved by integrating two genetic algorithms (GA) and the particle swarm optimization algorithm (PSO). The results of this research show that the integration of two algorithms, PSO and GA, provides a better answer than if only one meta-heuristic algorithm is used to solve the problem. It is worth mentioning that in the current research, the data of Tipax Company was used to locate the hubs and local tours routing.