Reliability improvements in aircraft maintenance planning and scheduling under uncertainty

Aircraft maintenance planning and scheduling is a complex problem due to large number of components involved at various planning and execution levels, and the size/nature of resource-intensive maintenance projects. This paper presents an integrated approach for improving reliability in maintenance planning and scheduling under uncertainty through unitary structures and associated forward planning capabilities. Maintenance requirements under uncertainty are incorporated using unitary structuring technique and is taken into consideration at the time of overall planning. When unplanned maintenance is warranted, forward planning can be executed for unplanned maintenance for finite loading of resources and availability of materials. This is demonstrated using a practical example drawn from the industry. The paper concludes that key improvement areas on the planning and scheduling processes under uncertainty are simultaneous planning of materials, operations and resources involved, forward planning of operations/tasks, and finite loading of resources. Potential benefits from improvements include reduction in spare-parts inventory, shorter turn-around times and cost reduction in overtime.