Computation time is reduced substantially.

An improved method of model-based diagnosis of a complex engineering system is embodied in an algorithm that involves considerably less computation than do prior such algorithms. This method and algorithm are based largely on developments reported in several NASA Tech Briefs articles: “The Complexity of the Diagnosis Problem” (npo-30315), Vol. 26, No. 4 (April 2002), page 20; “Fast Algorithms for Model-Based Diagnosis” (npo-30582), Vol. 29, No. 3 (March 2005), page 69; “Two Methods of Efficient Solution of the Hitting-Set Problem” (npo-30584), Vol. 29, No. 3 (March 2005), page 73; and “Efficient Model-Based Diagnosis Engine” (npo-40544), on the following page.