Aircraft Routings and their Impact on Airline Delays

Delays are a serious problem in airline industries worldwide, causing severe economic damage to a multitude of companies and societies. The research on delay causes as well as measures of delay reduction has been vast over the past decades, contributing rich insights to the matter. In particular, the airline planning, crew pairing, and aircraft scheduling process and its optimizations have received considerable attention in literature. This dissertation focuses on two of the main drivers of airline delay. First, a large part of daily airline delays is caused by network effects such as delays in the national aviation system and delays being propagated through the network on one day of operation. Research on airline delays has primarily focused on the macro perspective, thus analyzing entire domestic and global airline networks. Consequently, assuming a micro perspective on single aircraft routings and their delay implications still has considerable research potential. The underlying work scrutinizes selected strategies to create more robust aircraft routing schedules in the daily flight network. One of these strategies is reducing the hub connectivity in routings. Another strategy is creating swap opportunities for aircraft of the same type. A third strategy is to substitute routings with certain topologies less prone to delays by more efficient aircraft routings. While all three strategies have already received attention in literature, novel ways of analysis are applied providing a valuable addition to pertinent work. Also, large real-life datasets are used to empirically verify the corresponding research assumptions. Another key driver of daily airline delays are bad weather conditions. A comprehensive analysis of pertinent literature has revealed a multitude of different approaches to analyze weather delay. The underlying work aligns various approaches and builds an econometric model to guide decision-making on how to include weather more efficiently into research on airline delays. The research and analysis conducted in this dissertation provides various possibilities of real-life application. Planners in aircraft scheduling departments of major airlines can utilize the conclusions made to improve the robustness of daily aircraft schedules and to gain more insights the handling of weather-related delays. In addition, fellow researchers are provided with suggestions how to enhance the applied measures to adjacent or even more detailed areas of analysis. This dissertation is comprised of a synopsis preparing the separate research studies and depicting their integrative context. Following the synopsis, the dissertation includes three separate studies, of which the first two studies have been published in scientifically recognized journals with the third study being a working paper. Subsequently, a cross-study conclusion provides an integrated and final view on the underlying dissertation.