Fault Tree Analysis by List-Processing Techniques
The paper outlines an approach for AND-OR-NOT fault-tree analysis which uses simultaneously logical or qualitative and numerical or quantitative information structured in the tree. The analysis is carried out in two steps: search of the most important minimal cut-sets (MCS), computation of the availability and reliability for the cut-sets and for top events. The paper describes in detail the algorithms applied in the first phase: for the simplification of the tree, for the use of the cut-off, for the evaluation of the error introduced by the cut-off, for the search of the cut-sets in order of importance taking into account quantitative (probability) and qualitative (dependencies between events or gates) information, for the optimization of the process of analysis in order to reduce the number of cut-sets to be minimized, for the analysis of the NOT operators. These algorithms are based on the use of list processing techniques for the direct manipulation of graphs. The algorithms have been implemented in computer codes SALP-3 and SALP-4 for which examples of application are given.
KeywordsPrimary Event Boolean Function Repeated Event Minimization Procedure Disjunctive Normal Form
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