Model for operational daily airline scheduling

Perturbations in carrying out a schedule are occurrences which happen from time to time and there are numerous factors behind them. Cancelled or delayed flights can be caused by meteorological reasons, technical reasons, late or absent crew members, etc. One or more aircraft from an airline fleet might be taken out of operation due to technical reasons and the airline has to operate with a reduced number of planes. This paper presents the results of an effort to define a new daily airline schedule in this situation so that the total number of cancelled flights is minimized. Should there be several airline schedules with an equal total number of cancelled flights, the schedule with the minimum total passenger delay on flights to be performed is chosen. A heuristic algorithm is developed to solve this lexicographic optimization problem and is tested on numerical examples.