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