The problem of generating crew bidlines

Most US airlines generate pairings (or several-days-long work schedules) for airline crews and then string these pairings together into efficient month-long assignments or bidlines. In addition to meeting all relevant federal and union regulations, the generated bidlines must meet unwritten quality-of-life criteria. We developed an efficient optimization-based system for a major US airline to address this problem. It takes into account all relevant federal and union regulations and possesses a host of parameters that schedulers use to control the quality of the bidlines generated. The benefits from the system include reducing the time and resources needed to generate bidlines, improving crew utilization, and the ability to conduct what-if analyses to assess the impact of changes in the work rules and environment.