PROJECT TITLE :

An Imperfect Fault Coverage Model With Coverage of Irrelevant Components

ABSTRACT:

This paper addresses the coverage (including identification and isolation) of irrelevant elements in systems with imperfect fault coverage (IFC). In fault-tolerant systems, a single not-covered part fault may thwart the automatic recovery mechanisms, and result in a system or subsystem failure. The models that think about the consequences of IFC are known as coverage models (CMs). In traditional CMs, except those considering useful dependency (a similar concept to relevancy but with different assumptions and semantics), coverage is sometimes restricted to faulty components irrespective of their relevancies. Consequently, an operational but irrelevant component can not be isolated, and might threaten the system by its future uncovered (not-covered) failures. Although the system is generally assumed to be coherent, that implies the relevancy of each element within the initial system state, the ancient CMs don't consider the fact that an initially relevant element could become irrelevant once the failures of different components. We tend to propose the irrelevancy coverage model (ICM) to hide the irrelevant elements in addition to the faulty parts. In the ICM, a part will be isolated from the system whenever it becomes irrelevant (even it's not failed), such that its future not-lined failures can not affect the system anymore. By incorporating the coverage of irrelevant parts, the ICM release a new value-effective approach to improve system reliability without extra redundancy.