Inherent delays and operational reliability of airline schedules

This paper explores the inherent delays of airline schedules resulting from limited buffer times and stochastic disruptions in airline operations. The reliability of airline schedules is discussed and a set of measuring indices is developed to evaluate schedule reliability. It is found that significant gaps exist between the real operating delays, the inherent delays (from simulation) and the zero-delay scenario. Delay propagation and its impact on schedule reliability are also discussed. Results show that airline schedules must consider the stochasticity in daily operations. Schedules may become robust and reliable, only if buffer times are embedded and designed properly in airline schedules.