BITE availability under operational constraints

An operational system (OS) supported by a built-in test equipment (BITE) string is embedded in an operating environment that requires a high level of OS and BITE string availability. The BITE string availability expression is derived using a model with operational constraints posed by both the OS requirements and the support-logistics system. The resultant BITE availability expression is formulated as a function of the BITE string MTBF, mean fault detection delay of the BITE string test scenario and the mean logistics delay of the support system. The OS availability requirement/specifications is partitioned into the constituent elements of MTBF and MTTR where the fault isolation time element of MTTr is coupled to the BITE string availability. BITE availability calculations are subsequently carried out using the developed methodology