Impacts and Challenges. Most major airlines use optimization tools to partially or fully
generate their crew schedules, with significant economic impacts. Already in the 1960s, airlines were
solving crew pairing problems to reduce costs and
automate their burdensome manual planning process
(Arabeyre et al. 1969). With advances in optimization
and computing, crew pairing solvers became increasingly sophisticated and applicable. Using advanced
heuristic techniques, Anbil et al. (1991) achieved cost
savings at American Airlines of $20 million dollars
annually, representing an increase in crew utilization
of 1.5%.