Failures of solid-state electronic components are often caused by manufacturing defects. Typically, a small proportion of the manufactured components has one or more defects that cannot be detected in a simple inspection but that will eventually cause the component to fail. If a component has no such defects, the probability that it will fail under carefully controlled conditions is virtually 0. By assuming a time-to- failure distribution for the units that are susceptible to failure from manufacturing defects, laboratory life tests of limited duration can be used to estimate the proportion of units that have such defects and the parameters of the assumed time-to-failure distribution of the defective subpopulation.
The purpose of this article is to outline methods for analyzing life test data from life tests for ”limited-failure” populations. Applications are described and a numerical example is included.