An Optimum Model for Hub-and-Spoke Network Based on the Current Demand (Case Study: Iran Airport Network)

Air transportation has an important position among the other modes of transportation due to its significant impact in the economy and welfare of a society. Within the several components of air transportation market, flight network plays a fundamental role and considerably affects the airlines revenue. Improvement of the network system requires an accurate plan and programming. Hub-and-spokes are of further interest; as such networks reduce the operational costs, create proper ground for flight network development and extension, and help in competition. However, several models have been introduced for hub-and-spokes design purposes based on the diversity of the effective factors, decision-making variables and different forms of the network. Generally speaking, hub-and-spokes are categorized into two principal sectors: single allocation and dual or multiple allocations. Within a single allocation, traffic is accumulated in a single hub and then distributed to the destinations, while within a dual-allocation network, the gathered traffic at the first hub is again distributed to another hub before directing it to the final destination. This research presents a linear model for hub-and-spokes evaluation and planning, determining optimum flight routes and fleet assignment. The model considers both direct flights and hub connections, and outputs an optimum network based on the mixture of these two options. Sets of airport connections are so designed to well cover all the necessary inter-airport trips. This particular is done by utilizing hub-and-spoke system as the airport networks. To fulfill the requirements of the study location (Iran), in this paper, single allocation was selected to develop the models, meaning that just one hub has been considered in the modeling process. Inter-airport demands of the passengers were inputted in the network and the model works only for passenger transportation. The objective was to design the hubs so as to obtain an optimum network. In other words, the model is to suggest the best option with which the demand is handled cost-effectively. Trips are planned to be either direct or meeting a one-hub maximum. As the model is to minimize the cost, such variables as demand for variety of routes and type and quantity of the available aircrafts were included. The model was developed in two stages to ease the process.