Why are transportation problems popular applications for
In the early 1970s, many researchers were trying to apply mathematical
programming to business problems. The transportation problem was often
discussed as an application that would benefit from computerization.
Why? I think it is because this type of problem can be formulated
quantitatively and because such problems are often complex enough to
benefit from using a model. Also, the allocation of transportation
resources among competing uses is of interest to business
decision-makers in a number of different industries. In general,
real-world transportation problems are often important!
We have seen many different software programs for solving transportation
problems, but the basic need remains the same. Managers want help in
allocating a scarce resource. The basic problem formulation (cf.,
Hitchcock, 1941) has been adapted and expanded to a number of
situations. A major application is scheduling airline routes. The
following examples help explain why solving transportation problems are
important to airlines.
David Field in USAToday on April 19, 1999 explained briefly how airlines
make decisions about adding flights. Continental Airlines bases its
route and schedule decisions on daily ticket data. Continental uses a
computer program developed by American Airlines' Sabre unit. Field
quoted Robert Merz, director of network operations at United, "You
schedule to maximize profit ..."
At about the same time, Jessica Davis reported in InfoWorld that using
the "Broadbase data mart, United's staff of 60 analyst/schedulers,
typically MBA/economists, can load 'what if' scenarios -- testing
whether a new flight to Chicago would be more profitable using a larger
or a smaller aircraft". She noted schedulers take into consideration
passenger demand, constraints of airports, the maintenance needs of the
aircraft, the cost of flying individual aircraft, crew resources, and
Davis quoted Bob Bongiorno, United Airline director of research and
development, "Scheduling is the single most important thing we do at
this airline." Bongiorno said "We've got to fly to the right places with
the right frequency at the right times to make money."
Recently, Southwest Airlines implemented CALEB(TM) Technologies'
CrewSolver DSS to reduce the cost from traffic control delays and
mechanical and weather-related disruptions. For more information, check
the April 9, 2001 press release from CALEB Technologies at
So using Model-Driven DSS to solve transportation problems can improve
profitability!! On a cautionary note Professor N. K. Kwak noted almost
30 years ago that "mathematical programming provides quantitative bases
for management decisions -- bases with which management manipulates and
controls various activities to achieve the optimal outcomes of business
problems. Management can make better and more effective judgment by use
of mathematical programming. However, it is no substitute for the
decision maker's ultimate judgment." (p. 6)
Davis, J. L. "United overhaul brings decision-making down to earth",
InfoWorld, March 1, 1999.
Field, D. "Airlines pursue the trail of bucks", USAToday, April 19, 1999
at URL http://www.usatoday.com/life/travel/business/1999/t0419ad.htm.
Hitchcock, F. L. "Distribution of a Product from Several Sources to
Numerous Localities", The Journal of Mathematics and Physics, vol. 20,
August 1941, pp. 224-230.
Kwak, N. K. Mathematical Programming with Business Applications. New
York: McGraw-Hill, Inc., 1973.