Ejemplo De Una Investigación De Operaciones.

A New Era for Crew Recovery at
Continental Airlines
Gang Yu
Department of Management Science and Information Systems, McCombs School of Business,
University of Texas at Austin, Austin, Texas 78712

Michael Arguello • Gao Song • Sandra M. McCowan
¨
CALEB Technologies Corporation, 9130 Jollyville Road, Suite 100, Austin, Texas 78759

Anna White
Continental Airlines, 1600 Smith Street,Houston, Texas 77002
yu@uts.cc.utexas.edu • mike.arguello@calebtech.com • mark.song@calebtech.com
sandy.mccowan@calebtech.com • awhite@coair.com

Airlines face schedule disruptions daily because of unexpected events, including inclement
weather, aircraft mechanical problems, and crew unavailability. These disruptions can cause
flight delays and cancellations. As a result, crews may not be inposition to service their
remaining scheduled flights. Airlines must reassign crews quickly to cover open flights and
to return them to their original schedules in a cost-effective manner while honoring all government regulations, contractual obligations, and quality-of-life requirements. CALEB Technologies developed the CrewSolver decision-support system for Continental Airlines to generateglobally optimal, or near optimal, crew-recovery solutions. Since its implementation, the
system has dealt successfully with several high-profile events, including the December 2000
and March 2001 Nor’easter snowstorms, the June 2001 Houston flood, and most dramatically,
the September 11th terrorist attacks. In each case, Continental recovered quickly and obtained
overall benefits worth millions ofdollars. Continental estimates that in 2001 the CrewSolver
system helped it save approximately US $40 million for major disruptions only.
(Transportation: scheduling, personnel. Decision analysis: systems.)

O

n an average day in the United States before September 11, 2001, 15 to 20 percent of commercial
airline flights were delayed more than 15 minutes and
one to three percent of flights werecanceled. The
United States Inspector General reported that, during
2000, more than one in four flights (27.5 percent) were
delayed, canceled, or diverted, affecting approximately 163 million passengers (United States Inspector
General 2001 report). Airlines spend a great deal of
time and energy planning and scheduling their operations. They use state-of-the-art processes and automated toolsto create plans and schedules that maximize expected revenue and minimize operational

0092-2102/03/3301/0005$05.00
1526-551X electronic ISSN

costs. The resulting plans and schedules tightly couple
resources, such as aircraft and crew. In general, execution of these plans during normal operations makes
the airlines profitable; however, such tight schedules
leave the airlines vulnerable todisruptions.
During the day of operations, such disruptions as
inclement weather, mechanical problems, the Federal
Airline Administration (FAA) air traffic control (ATC)
and ground delay program (GDP), and sick crew frequently jeopardize an airline’s ability to execute its
schedule as planned. Airlines structure their services
as networks and design their complex schedules to
achieve highresource utilization. As a result, any disInterfaces, 2003 INFORMS
Vol. 33, No. 1, January–February 2003, pp. 5–22

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YU, ARGUELLO, SONG, McCOWAN, AND WHITE
Continental Airlines

ruption has an immediate impact, resulting in flight
delays and cancellations, and may also propagate additional disruptions in operations throughout the day
and into subsequent days. For example, the skies may
beclear and blue with no severe weather anywhere in
the United States, and yet a flight may be delayed an
hour because a pilot scheduled to fly becomes ill and
no replacement pilot is available. With their narrow
profit margins, airlines lose money during irregular
operations when schedules are disrupted.
In 1994, Continental Airlines, through its primary
information-technology provider,...