Abstract: The present invention is a fault tree analysis system, comprising: k/n conjunction weeding means for weeding a conjunction including disjoint basic k/n gates and/or disjoint simple k/n gates and removing the conjunction if its order is greater than a given maximal order of minimal cut sets.

Abstract: The present invention is a fault-tolerant system comprising: system failure logic means for editing system failure logic; and irrelevant component coverage means for identifying irrelevant components not having an effect on the system failure logic and isolating the irrelevant components based on the system failure logic provided by the system failure logic means.

Abstract: The present invention is an identification system comprising: an irrelevance trigger interpreting section for calculating a logical formula of irrelevance triggers for a component in a system from a cut set logical formula f of a system failure; and minimal cut set evaluating means for minimizing the logical formula of the irrelevance triggers, which has been calculated by said irrelevance trigger interpreting section, to calculate the irrelevance triggers for said component.

Abstract: The original MCS of a system fault tree includes sufficient conditions required for a top system hazard. If a fault occurs in a component and the component is restored, the current MCS of a system and the critical components can be calculated on the basis of the original MCS by means of several calculation patterns.

Abstract: The present invention is a fault tree system reliability analysis system, comprising: k/n gate splitting means for splitting a disjunctive k/n gate with inputs of OR gates into disjoint conjunctive k/m gates (m?n) without input of OR gate.

Abstract: The present invention is a minimum cut set calculation system for calculating minimum cut sets of a fault tree with binary decision diagram (BDD), comprising: subtracting means for, from one of two sub-BDDs of an input BDD, removing redundant paths included in the other sub-BDD using a recursive function comprised of a recursive case and a base case, wherein said subtracting means comprises equivalence removing means for, when said two sub-BDDs are equivalent, outputting a terminal node 0 in said base case.

Abstract: The present invention is a fault-tolerant system comprising: system failure logic means for editing system failure logic; and irrelevant component coverage means for identifying irrelevant components not having an effect on the system failure logic and isolating the irrelevant components based on the system failure logic provided by the system failure logic means.

Abstract: The present invention is a fault tree analysis system, comprising: k/n conjunction weeding means for weeding a conjunction including disjoint basic k/n gates and/or disjoint simple k/n gates and removing the conjunction if its order is greater than a given maximal order of minimal cut sets.

Abstract: The present invention is a fault tree system reliability analysis system, comprising: k/n gate splitting means for splitting a disjunctive k/n gate with inputs of OR gates into disjoint conjunctive k/m gates (m?n) without input of OR gate.

Abstract: The present invention is a system for static fault tree analysis from system models comprising: system configuration input unit that inputs system configurations and top events of the systems to be analyzed; system model library that stores a set of system architecture models and component error models; and fault tree analyzer that analyzes fault trees of the system from the top events in terms of decomposition rules defined in the component error models. The system configurations and top events are instances of the system architecture models and the fault events of the component error models stored in the system model library, respectively. The system architecture models delimit classification of and definitions of physical and semantic relations between different components. The component error models define different fault events of components and their Boolean logic relationships called decomposition rules which cover both functional and sequential dependencies for fault tree analysis.

Abstract: The original MCS of a system fault tree includes sufficient conditions required for a top system hazard. If a fault occurs in a component and the component is restored, the current MCS of a system and the critical components can be calculated on the basis of the original MCS by means of several calculation patterns.