Integer model approach for hub location problem in air cargo transportation

The models that are developed for hub location problems and hub and spoke networks have been widely used over the past two decades. In the hub and spoke network structure, a facility which has the central location serves as a hub. Flows outgoing from other facilities are collected and grouped in the hub. All of the flows depart from this hub either to other hubs or directly to their destinations. This centralization and expansion of operational network provide the benefits of economies of scale. Hub and spoke networks increase the profits and decrease the costs of airlines.In this study, it is aimed to develop a new aspect about hub location problems. The effects of aircraft types and characteristics of the sector over the hub locations have been investigated. Starting from the characteristics of the air transportation and the aircraft performance mixed integer linear models related with the multiple allocation p-hub median and hub location problems with fixed costs; and also a mixed integer non-linear model to be used in the problem of selection of aircraft types in p-hub median have been developed. Models were coded in GAMS software. CPLEX solver was used in the solution of multiple allocation p-hub median and hub location problems with fixed costs. DICOPT solver was used in the solution of the multiple allocation p-hub median and the corresponding selection of the appropriate aircraft types. It was found that the constraints and parameters have an important effect on the hub location and allocation. It was shown that the models may also be used in the problem of selection of the most appropriate aircraft corresponding to different flight routes.