The Air Force Can Improve Its Forecasts of Aircraft Spare Parts Requirements

NSIAD-85-2: Published: Nov 19, 1984. Publicly Released: Nov 19, 1984.

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Harry R. Finley
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GAO evaluated the Air Force's methods for developing and applying flying hour program ratios in estimating future requirements for consumable spare parts for aircraft.

The Air Force forecasts spare parts requirements by calculating the ratio of future flying hours to past flying hours for an aircraft using a specific part and then applying this ratio to the historical demand for the part. GAO found that the Air Force is overestimating its need for parts for some aircraft which are being phased down or phased out and, at the same time, underestimating its need for parts for some aircraft with increasing flying hour programs. As a result, the Air Force may spend millions of dollars for parts before they are needed or which may not be needed but fail to purchase those spare parts which are needed.

Recommendation for Executive Action

  1. Status: Closed - Not Implemented

    Comments: DOD does not intend to implement the portion of the recommendation that procurement leadtime be used in ratio computations instead of shorter fixed time periods, because they believe the change could result in potention excess material. GAO does not agree with DOD; however, GAO plans no further action at this time because DOD is adamant about refusing to make the change.

    Recommendation: The Secretary of the Air Force should direct the Commander, Air Force Logistics Command, to implement improved procedures and controls for estimating future requirements for system support stock fund items. Such procedures and controls should: (1) require appropriate management review to ensure that equipment specialists correct and maintain current, accurate application data to compute flying hour ratios and verify the accuracy of the application data at a reasonable time interval; and (2) revise the forecasting system so that the computed flying hour ratio takes into account the flying hours on the actual aircraft model and series using the part and the estimated lead time needed to obtain the part.

    Agency Affected: Department of Defense: Department of the Air Force


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