Single Fault Isolation – Also called Common Cause Isolation. A method of fault isolation that proceeds under the assumption that all "failed" tests in a diagnostic session are due to a single malfunction or fault. Although frequently used as the basis for diagnostic analyses (such as testability) during the design phase, single fault isolation cannot consistency produce accurate results when multiple components are simultaneously malfunctioning during diagnosis. The degree to which diagnostic accuracy suffers depends on the likelihood of multiple failures (taking into consideration the possibility of dependent failures and the length of the interval between diagnostic sessions) and the extent to which single failures can produce the same test signature as multiple failures. (Compare with Multiple-Failure Isolation).
