MIL-R-55231

Abstract

This specification covers the general reliability procedures for use on production contracts for electronic equipment. Detail requirements will be specified in the individual equipment specification. In case of conflict, the equipment specification shall govern. <br>This specification covers the following three phases of contractual effort, which will be prescribed individually or collectively: <br><i>Preproduction reliability measurement:</i> The measurement of reliability of a preproduction sample of one or more units, sets, or systems. <br><i>Pilot-production reliability inspection:</i> The measurement or acceptance inspection of the reliability of a pilot production sample of two or more units, sets, or systems. <br><i>Quantity-production reliability inspection:</i> The acceptance inspection, by sampling, of quantity production of units, sets, or systems. <br>This specification is applicable when either of the following procedures is to be employed: <br>A mean-time-between-failures (MTBF) is not specified. The contractor conducts specified reliability testing on preproduction and pilot production items. A minimum MTBF for production is then established by analysis (statistical and other) of the test data. <br>A MTBF is cited in the equipment specification or in the contract. <b><u>Intended Use:</u></b> This specification, when specified as a subsidiary document in an individual equipment specification or in the contract, provides for quantitative reliability requirements in production contracts for new electronic items. It is understood that the equipment is repairable and that, during the normal period of life of the equipment, the failure rate is constant and the distribution of time between failures is exponential. <br>