Calculation of Top Event Probability of Fault Tree using BDD

BDD를 이용한 사고수목 정상사상확률 계산

  • Received : 2016.01.19
  • Accepted : 2016.02.18
  • Published : 2016.03.31


As the number of gates and basic events in fault trees increases, it becomes difficult to calculate the exact probability of the top event. In order to overcome this difficulty the BDD methodology can be used to calculate the exact top event probability for small and medium size fault trees in short time. Fault trees are converted to BDD by using CUDD library functions and a failure path search algorithm is proposed to calculate the exact top event probability. The backward search algorithm is more efficient than the forward one in finding failure paths and in the calculation of the top event probability. This backward search algorithm can reduce searching time in the identification of disjoint failure paths from BDD and can be considered as an effective tool to find the cut sets and the minimal cut sets for the given fault trees.


Binary Decision Diagram;Cut Set;Failure Path;Fault Tree;Minimal Cut Set


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  1. Failure Analysis to Derive the Causes of Abnormal Condition of Electric Locomotive Subsystem vol.41, pp.2, 2018,


Supported by : Ministry of Land, Infrastructure and Transport of Korean government