The Application of Overstress Testing-to-Failure to Airborne Electronics-A Status Report

Several years of study and actual testing have answered many of the previously controversial questions about the application of environmental overstress testing-to-failure as a useful tool for reliability evaluation. The answers included the fact that more than 65 percent of the failures occurring under overstress environments were duplicates of experienced operational failures. Improvements of 5 to 1 in reliability levels have resulted from application of results of overstress tests, which consumed less than 200 hours of actual test time. Overstress tests have also been used as a method of evaluating multiplesource designs. The first in a required series of indices has been derived, which may assist in the eventual use of overstress testing for reliability index measurement.