A manufacturer's estimate of field hours

A manufacturer can use elapsed time indicator (ETI) records and production item shipment records to estimate total field operating hours on a product line versus program age. Logistic support record formats lend themselves to this type of analysis. The recommended approach was tested by comparing its results to user's records of flight hours over a six year period. It is concluded that the ETI readings and logistic records provide a good estimate of field operating hours which can be used to measure reliability characteristics. Measurements are useful in total quality management as well as in reliability growth management.<>