Presenting an Integrated Hub Location Model with a Flexible Scheduling Approach in Air Transportation

Currently, due to the country's sanctions, airlines face restrictions on access to aircraft, which has affected the efficiency of the national air transportation network. However, with proper planning, optimal utilization of available aircraft, and route optimization through the hub location problem, it is possible to achieve better efficiency and mitigate the losses and costs caused by sanctions. In this paper, an integrated model for hub location with a flexible scheduling approach in air transportation is presented. This model not only determines the locations of hubs but also optimizes the routing and scheduling of each aircraft simultaneously, considering their initial locations and the constraint of a limited number of available aircraft. Unlike other studies in the literature, this research considers the presence of vehicles at nodes and the necessity of passenger arrival at each vehicle as a prerequisite for passenger transfers, making the problem more aligned with real-world conditions. The proposed model is solved using GAMS software, and its results are validated using two datasets: CAB and Iranian air passenger data for the year 2022. The findings indicate that, given the model's assumptions, increasing the number of hubs, expanding aircraft capacity, and distributing aircraft across nodes instead of concentrating them in specific locations can lead to cost reductions, although it also increases the model's complexity. Finally, recommendations for future research to improve the model are provided.