Fleet Assignment Problem
ABARA
American Airlines
Decision Ti'chnohi^ics
PO Box 619616
Dallasll'ort Worth Airport, Texas 75261-9616
We formulated and solved the fleet assignment problem as an integer linear programming model, permitting assignment of two or more fleets to a flight schedule simultaneously. The objective function can take a variety of forms including profit maximization, cost minimization, and the optimal utilization of a particular fleet type. Several departments at American
Airlines use the model to assist in fleet planning and schedule development. It will become one of 10 key decision modules for the next generation scheduling system currently being developed by American Airlines Decision Technologies.
A
merican Airlines' schedule comprises a list of over 2,300 flights per day to over 150 different cities utilizing over 500 jet aircraft. This schedule is produced by considering an existing set of flights, traffic revenue forecasts, available resources such as aircraft, gates, and associated operating costs.
Within a schedule, there is a repeating pattern of flights, with the pattern covering one day or several days, usually a
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week. The goal of the fleet assignment process is to assign as many flight segments as possible in a schedule pattern to one or more aircraft types (American currently operates ten fleet types) while optimizing some objective and meeting various operational constraints,
The best aircraft for each flight leg is not always the one with the highest benefit because, among other reasons, aircraft must be routed for maintenance, and the
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INTERFACES 19: 4 July-August 1989 (pp. 20-28)
AITIXATIONS
FLEET ASSIGNMENT number of available aircraft is limited.
Objectives that