On some tests designed to demonstrate statistically the required mean life

Abstract

Two Life Tests recently suggested by various Government Agencies are described in sections 1 and 4 respectively and the consequences of their application are discussed. It is shown that to satisfy them with some reasonable probability the manufacturer has to produce equipment of much higher standard than initially stipulated. Although the tests are meant to be designed so that the probability fi of accepting an inferior equipment would be appropriately small, it is shown that the second test does not satisfy this condition leading to the acceptance of inferior equipment with much greater probability (section 7).