Abstract: Considered the disjunction between current spare part demand prediction methods and system top-level design requirements, as well as the large deviation between prediction results and readiness requirements of equipment system, the relationship between achieved availability and system level fill rate should be established by using augmented achieved availability. Analyzed the influence factors on the fill rate, the fill rate could be allocated to subsystems and LRU level for the prediction of spare part demand. A case on aircraft spare part demand prediction was introduced, and the prediction results verified the method's feasibility and applicability. The spare part demand prediction integrating equipment bottom-level design elements can be well consistent with the system top-level design requirements, and the proposed method is helpful to realize the design requirement and enhance the prediction operability.

Key words: probabitity, spare part demand, achieved availability, fill rate, line replaceable unit