Built-in-test in support system maintenance

This article looks at the state of BIT (built-in-test) in test and measurement instruments, explains BIT's effect on system readiness, and presents ideas on how to improve BIT technologies and standards. The following topics are discussed: circuit level BIT (built-in self-test); module level and line replaceable units (LRU); system-level self-contained testing; instrumentation BIT history; BIT fault coverage and isolation in support system maintenance; BIT development process; pitfalls and limitations of BIT; BIT effectiveness in support system maintenance and availability.