Improvement of Aircraft Availability and Optimization of Component Costs by Pre-Emptive Removal of Targeted Components 2019-01-1341
Maintenance expenses of complex repairable systems, like aircraft, have been a frequent target of cost-cutting measures. One common strategy focuses on extracting as much service life as possible out of various non-critical system components by letting those components “run to failure”, based on the belief that this would be the best way to achieve the lowest maintenance costs. One of the biggest drawbacks of the “run to failure” approach is that it comes at the cost of lower asset availability, since the failure of one of those components will nearly always lead to an unscheduled maintenance event, typically right when the operator wants to use the asset. Furthermore, the idea that running components to failure will reduce costs is fundamentally flawed, since it fails to account for the extra costs incurred from those unscheduled maintenance events. To combat the impact of those unscheduled maintenance events, many OEMs, operators, and component manufacturers are looking to prognostics to get an advanced notice of an impending failure, so the subject component can be replaced before it completely fails. However, for technological and/or economic reasons, prognostics are not a viable option for the vast majority of components. As an alternative to running components to failure, asset operators and maintainers need another strategy to minimize the impact of unscheduled maintenance events for components without prognostics that balances component utilization and the costs associated with unscheduled maintenance events against overall asset availability. This paper presents a methodology for evaluating the trade-offs between these factors and shows how this approach can potentially reduce overall asset life-cycle costs.