Three-Valued Diagnosable Systems: Diagnosability, Optimal Design and Fault Identification Algorithm

A three-valued model for computer system diagnosis is proposed in this paper. A subsystem is regurded as composed of two components, a task processor and a communication processor. Accordingly, subsystem faults are classified as type 1 or type 1/2 faults, representing subsystem faults with communication processors being faulty or those with communication processors being fault-free, The concepts of virtual tests and t¹/t^1/2 fault diagnosis are introduced. And t¹/t^1/2 fault diagnosis with centralized control and that with distributed control are studied respectively. The problems addressed here include diagnosability, optimal design and fault identification algorithm. The results show clearly that t¹/t^1/2 fault diagnosis can afford to identify significantly more faults than t-fault diagnosis under the same structural constraint.