Fault trees for clusters tolerating failure or disconnectedness of a single node
Given a K-nodes cluster (subnetwork) in an N-nodes network, the (Boolean) fault tree function for the connectedness of at least K?1 intact nodes out of the above K nodes is determined. This function is primarily formulated as a function of mutually dependent variables, viz., the top event variables of various point-to-point connectivity (so-called s,t-) problems. The minimization of the number of s,t-problems involved will be a major concern. The main contribution of this paper is seen in the conceptual clarity of the approach, whereas the computational complexity for real life problems still needs improvements. (The analysis of the fault trees found, resulting in system unavailability, MTTF, etc., is not pursued here.) A preliminary version of this paper was reviewed for and presented at EWDC-7 (European Workshop on Dependable Computing 1995; without proceedings).
fault tree graph connectedness k-terminal problem fault tolerance