A new decomposition algorithm for complex voting gates processing in qualitative fault tree analysis
Jin Wang, Shanqi Chen, Fang Wang, Liqin Hu · Proceedings of the Institution of Mechanical Engineers Part O Journal of Risk and Reliability · 2015
Fault tree analysis technique is one of the main methods of reliability analysis. In a fault tree, voting gate, namely k out of n ( k/ n) gate, is one of the standard Boolean logic constructs which can represent AND, OR and NOT gates. It is traditionally expanded into a combination of AND and OR gates, but such expansion results in combinatorial explosion problem in determining minimal cut sets of the fault tree for even a not very big n, especially when the voting gate inputs are complex sub-trees rather than basic events. In this article, a new decomposition algorithm based on expanded combination formula which can decompose the voting gates more quickly while the space and time complexity is lower than the traditional expansion was proposed. The results of experiments on fault trees with voting gates showed that this algorithm was more efficient than the traditional expansion method and the recursive decomposition method.