Express Air Network Design with Multi-Hub Flexible Connections

We present a model for the Air Network Design for the next day delivery within an Express company. Most of the existing models rely on a pre-definition of connections for each commodity through a specific hub. We present a model in which we integrate the decision of connectivity simultaneously with the network design. When two hubs are so close from each other that they can serve (almost) the same nodes, the results show that savings can be obtained by taking both decisions at the same time.