Uncertainty of test coverage: A challenge for state of the art integrated diagnostics

As electronics becomes increasingly more complex, it is becoming more difficult to assure that the internal and external tests cover the relevant fault universe. As the confidence in these tests becomes less certain, the hierarchy of Integrated diagnostics becomes compromised. In this sense, one might conclude that fault coverage is the most essential component of integrated diagnostics. By clearly defining the fault universe, even in the presence of literally millions of faults, we can establish a baseline for test coverage. As we overlay clearly defined tests and establish a relationship between faults and tests, we can reduce the test coverage uncertainty. The difficulty levels in this process are substantial but computer tools and fault-centered analysis can break the cost and complexity barriers.