Abstract
Airlines operate in an increasingly competitive market where they need to provide a world class flying experience, while reducing their operating cost and maximising aircraft availability, safety and reliability and profit margins. A key part of the operating cost of airlines is the maintenance cost during the operational phase of the aircraft life cycle. This applied research was inspired and focussed on the challenge of an airline that was experiencing the challenge of an increase in maintenance costs. The motivation was to identify cost drivers and assist in pointing to the areas that need improvement. The research was based on historical data and information on real maintenance costs and operations documented at the company. The research reviewed the methodology used for scheduled maintenance tasks and intervals, acceptable to the regulatory authorities, the operators and the manufacturers based on MSG-3 (Maintenance Steering Group). It is within this context and framework that the selected airline operated. The first stage of the research was an in-depth understanding of historical data on aircraft maintenance cost during the operational phase of the aircraft life cycle for the specific organisation. The analysis focussed on cost and key parameters such as aircraft flight hours, flight cycles, reported faults and dispatch reliability. The research identified that flight hours were strongly correlated with maintenance cost and identified the type of maintenance faults that constituted 80% of reported faults as per Air Transport Association (ATA) chapters. These identified systems can be a focus for cost control. An analytical approach and equations were then developed for the first time for the aircraft maintenance process based on index decomposition analysis to quantify the impact of flight hours on the increase in maintenance cost in relation to the operating context. The variables considered relate to the volume of activity (productivity), variety of activity (structure) and resource cost intensity of activity. Rebound effect analysis was then used to assess the contribution of maintenance cost effectives in reducing total costs when considered alongside increase in flight hours (more aircraft utilisation). The historical trend analysis has pioneered a modelling tool for quantitatively assessing the drivers for cost control in maintenance. This will be of use to airlines and maintenance researchers. Furthermore, the rebound effect analysis enables a new metric for evaluation of maintenance cost effectiveness while simultaneously considering increased aircraft utilisation (more flight hours). This sets the threshold on how to reduce total maintenance costs while making more flight hours.
Ph.D. (Engineering Management)