Abstract:
In airline scheduling a variety of planning and operational decision problems have to be
solved. We consider the problems aircraft routing and crew pairing: Aircraft and crew must
be allocated to flights in a schedule in a minimal cost way. Although these problems are not
independent, they are usually formulated as independent mathematical optimisation models
and solved sequentially. This approach might lead to a suboptimal allocation of aircraft and
crew, since a solution of one of the problems may restrict the solution of the problem solved
later. Also, when minimal cost solutions are used in operations, a short delay of one flight
can cause very severe disruptions of the schedule later in the day. We generate solutions that
incur small costs and are also robust to typical stochastic variability in airline operations.
We solve the two original problems iteratively. Starting from a minimal cost solution, we
produce a series of solutions which are increasingly robust. Using data from domestic airline
schedules we evaluate the benefits of the approach as well as the trade-off between cost and
robustness. We extend our approach considering the aircraft routing problem together with
two crew pairing problems, one for technical crew and one for flight attendants.