AirCROP: Airline Crew Pairing Optimizer for Complex Flight Networks Involving Multiple Crew Bases Billion-Plus Variables
Airline scheduling poses some of the most challenging problems in the entire Operations Research (OR) domain. In that, crew scheduling (CS) constitutes one of the most important and challenging planning activities. Notably, the crew operating cost is the second-largest component of an airline's total operating cost (after the fuel cost). Hence, its optimization promises enormous benefits, and even marginal improvements may translate to annual savings worth millions of dollars for an airline. However, CS is a combination of complex combinatorial optimization problems (with NP-hard computational complexity), namely crew pairing and crew assignment, which are solved sequentially. Here, crew pairing optimization aims at generating a set of flight sequences (each called a crew pairing) to cover a finite set of flight legs from an airline's timetable at minimum cost, while satisfying several legality constraints linked to the federations' safety rules, airline-specific regulations, labor laws, etc. Subsequently, crew assignment aims at assigning crew members to these optimal crew pairings. This research focuses on the critically fundamental step of CS, in that, a crew pairing optimization problem (CPOP) is formulated, and an optimization framework to solve the posed CPOP has been proposed. The distinctive contribution of this research relates to its tackling of a large-scale complex flight network for an airline (leading to more than a billion legal pairings/variables), and validation of the results by the research consortium's Industrial partner, GE Aviation.
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