MATHEMATICAL-MODELS IN AIRLINE SCHEDULE PLANNING - A SURVEY

The schedule is an airline's primary product, having the most influenc e (along with price) on a passenger's choice of an airline. Once an ai rline decides (at least tentatively) on a schedule, a host of related problems have to be resolved before it can consider the schedule feasi ble, and can proceed to market the schedule. Among these problems are traffic fore-casting and allocation that forecasts traffic on each fli ght leg for use in the fleet assignment model, fleet assignment that d ecides the fleet type of the aircraft flying the legs in the schedule, equipment swapping to change an assigned equipment type on a leg if a nd when necessary, through flight selection for determining which pair s of flights to market as one-stops (without any aircraft change), mai ntenance routing that develops aircraft rotations to provide adequate opportunities for overnight maintenance, and flight numbering to numbe r flights as consistently as possible with a prior schedule. Considera ble methodological and computational advances have been made in the re cent past in developing models and solution methods for almost all of the problems mentioned above. In this paper we survey these various mo dels and solution techniques.