Airline crew scheduling with time windows and plane-count constraints

Airline planning consists of several problems that are currently solved separately. We address a partial integration of schedule planning, aircraft routing, and crew scheduling. In particular, we provide more flexibility for crew scheduling while maintaining the feasibility of aircraft routing by adding plane-count constraints to the crew-scheduling problem. In addition, we assume that the departure times of flights have not yet been fixed and we are allowed to move the departure time of a flight as long as it is within a given time window. We demonstrate that such a model yields solutions to the crew-scheduling problem with significantly lower costs than those obtained from the traditional model.