The crew that scheduled savings of over $15,000,000
for Air New Zealand

Commercial airlines must solve many resource-scheduling problems to ensure that aircraft and crews are available for all scheduled flights. Those aircraft and their crews are among the most expensive of airline resources, so utilizing them in the most efficient way possible doesn't just make good sense, it makes large savings as well.

In the past, many airlines have spent many man-hours trying to develop optimization methods to solve their crew scheduling problems. Most of them failed, mainly due to inadequate methods and a lack of computer power. Even now many airlines persist in using heuristic or manual methods to solve crew-scheduling problems, in other words, trial and error – an expensive methodology and a very inefficient one.

On a simplistic level, the typical air crew scheduling problem consists of two important sub-problems: the tours-of-duty planning problem to generate minimum-cost tours of duty (sequences of duty periods and rest periods) to cover all scheduled flights, and the rostering problem to assign tours of duty to individual crew members. Between 1989 and 1999, Optima and Air New Zealand staff, in collaboration with The University of Auckland, developed eight application-specific optimization-based computer systems to solve all aspects of the planning and rostering processes for Air New Zealand's operations.

These systems have delivered substantial financial benefits to the airline by directly reducing the number of hotel bed-nights, meals, and other overseas crew expenses and by reducing the total number of crew required. Each application also reduced the costs of constructing and maintaining the crewing solution for the flight schedule.

Over the past ten years, Air New Zealand's fleet and route structure have increased significantly in size yet the number of people needed to solve the crew scheduling problem dropped from 27 in 1987 to just 15 in 2000.

A conservative estimate of the savings from the crew-scheduling optimizers is NZ$15,655,000 per year.