Prediction of Repair Times

Abstract

Maintainability prediction is by no means as well developed as reliability prediction. The only fully developed systems are described in US MIL HDBK 472 which is dated 1966. In 1973 this document was withdrawn and replaced by US MIL STD 471A which contains no prediction techniques. The methods described in US MIL HDBK 472, although applicable to a range of equipment developed at that time, have much to recommend them and are still worthy of attention. Unfortunately the quantity of data required to develop these methods of prediction is so great that with increasing costs and shorter design lives the author fears that such exercises may not be repeated. On the other hand calculations requiring the statistical analysis of large quantities of data lend themselves to computer methods and the rapid increase of these facilities makes such a calculation feasible if the necessary repair time data for a very large sample of repairs (say 10000) were available.