AUTOMATIC GENERATION OF EVENT TREES AND FAULT TREES: A MODEL-BASED APPROACH

In the past few decades, the increasing complexity in modern engineering systems has been driven by the integration of a large number of components whose operations may involve many disciplines (e.g., thermal-hydraulics, plant operations, cybersecurity). Most computational tools used by the industry and regulators for safety/reliability modeling of such systems are still based on the traditional fault tree (FT)/event tree (ET) approach which may not be able to capture complex interactions among system constituents, While the use of simulation tools has widely increased in the past few decades to improve fidelity of the reliability analysis, such as with the use of dynamic probabilistic risk assessment (DPRA) methods: i) modeling of the whole system under consideration with DPRA methods may be computationally expensive and unnecessary, and, ii) manual integration of DPRA models into existing state-of-practice PRA models (i.e., based on FTs and ETs) can be time consuming and prone to errors. The objective of this paper is to overcome this limitation by presenting several algorithms designed to automatically construct subsystem ETs and FTs from DPRA methods for integration into an existing ET/FT system model.