Abstract: An efficient algorithm of the test point selection and fault diagnosis strategy for complex systems, considering reliability and testing costs, is presented based on the dependency matrix. At first, according to the system dependency matrix, the testability measure is integrated with fault probability and testing costs, and new informationcalculating formulas are derived for fault diagnosis. Then, test points can be selected based on the fault diagnosis information values, and a more efficient fault diagnosis strategy can be constituted. The strategy ensures to accomplishthe system fault detection and isolation quickly by using fewer testing steps under less testing costs.

Key words: testability, test point, fault diagnosis, reliability, cost