Integrated Airline Schedule Planning

Abstract

A flight schedule defines a feasible plan of what cities to fly to and at what times. The task of airline schedule planning is to generate a flight schedule that achieves the most effective use of an airline’s resources. Typically, schedule planning is a sequential process. First, key decisions are made about the flight schedule and then, decisions are made concerning the matching of the airline’s fleet to the flights in the schedule. Finally, with all of these decisions fixed, crew planning is performed. These problems are solved sequentially, rather than simultaneously, primarily because of limitations in computer technology and solution algorithms. Simultaneous solution approaches are preferred, of course, because they do not create incompatibilities like those generated in sequential approaches and they might generate lower cost solutions.

We focus on the problem of quantifying the difference in solution quality between simultaneous and sequential solution methods for airline schedule planning. We describe an advanced solution approach that, while still sequential, begins to integrate the schedule planning process. We present a new model that incorporates downstreameffects into an upstream decision model. Using data provided by a large airline, we show that our approach is both tractable and capable of producing dramatically improved solutions to the overall schedule planning problem. Finally, we show that because of limitations imposed by computer hardware and solution algorithms. unlike current sequentially generated solutions, the solutions we generate are very close to the best possible solutions of a fully integrated solution process.