Airline Network Planning and Scheduling

19Integrated Schedule Design with the Itinerary‐based Fleet Assignment Model (ISD‐IFAM)

19.1 Introduction

In Chapter 14, the schedule design problem is described as an extension of the basic fleet assignment model (FAM). The problem allows flight schedule modification in terms of flight additions, flight deletions, and departure time adjustment for a limited number of flights. One main limitation of this approach is the lack of demand–supply interactions. In other words, it is assumed that the demand is constant and independent of any suggested schedule changes. However, if a flight is eliminated in a city‐pair, the passenger demand is expected to shift to other existing flights/itineraries serving that city‐pair. Similarly, adding a flight to the schedule might induce new demand and/or shift existing demand from other flights/itineraries to the new flight. A change in the demand pattern is also expected with any change in the departure time of the flights. Of course, one should expect that if a significant change is introduced to the schedule, the impact on the demand estimated for each flight would also be significant. As such, assuming fixed flight demand simplifies the integrated schedule design and fleet assignment problem. Disregarding this assumption would require the capability to predict how the demand is redistributed among the different itineraries/flights as a result of any proposed schedule modification.

In this chapter, the itinerary‐based fleet assignment model ...