A stochastic model for burn-in procedures in accelerated environment

Burn-in procedure is a manufacturing technique that is intended to eliminate early failures of system or product. Burning-in a component or system means to subject it to a period of use prior to being used in field. Generally, burn-in is considered expensive and so the length of burn-in is typically limited. Thus, burn-in is most often accomplished in an accelerated environment in order to shorten the burn-in process. A new failure rate model for an accelerated burn-in procedure, which incorporates the accelerated ageing process induced by the accelerated environmental stress, is proposed. Under a more general assumption on the shape of failure rate function of products, which includes the traditional bathtub-shaped failure rate function as a special case, upper bounds for optimal burn-in time will be derived. A numerical example will also be given for illustration.