An optimization model for assigning through flights

Non-stop flights are the first choice for passengers traveling from one city to another. In the absence of such flights, passengers must take connecting services (or connections) with two or more flights. A through flight is a type of connection that uses the same aircraft for the flights involved, which enables connecting passengers to remain onboard rather than deplaning to locate their departure gates at busy airports. The convenience of through flights gives them a marketing advantage over regular connections. For this reason, airline schedulers invest significant effort in building profitable through flights into the flight schedule. We have developed an optimization model for United Airlines for constructing the set of through flights that maximizes the through revenue for a schedule. The model eliminates the manual effort involved in assigning through flights and enhances the network contribution by at least ten million dollars annually.