Coldstart: Fleet Assignment at Delta Air Lines

Delta Air Lines flies over 2,500 domestic flight legs every day, using about 450 aircraft from 10 different fleets. The fleet assignment problem is to match aircraft to flight legs so that seats are filled with paying passengers. Recent advances in mathematical programming algorithms and computer hardware make it possible to solve optimization problems of this scope for the first time. Delta is the first airline to solve to completion one of the largest and most difficult problems in this industry. Use of the Coldstart model is expected to save Delta Air Lines $300 million over the next three years.