On the Reliability of a Worst Case Designed Nonredundant Circuit

A worst case designed circuit is defined and, based on observed component failure modes, a mathematical model for circuit reliability is obtained. A special case of the general model is then considered by assuming all the component failure rates to be equal. Using this simplified model it is established that a worst case designed nonredundant circuit is more reliable than the product of the reliabilities of its components. The mean time to failure (MTTF) is computed and it is shown that, for particular extreme values of the parameter p, the MTTF assumes the classical forms more frequently seen in the literature.