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Fuzzy evidence theory and Bayesian networks for process systems risk analysis

Yazdi, Mohammad; Kabir, Sohag


Mohammad Yazdi


Quantitative risk assessment (QRA) approaches systematically evaluate the likelihood, impacts, and risk of adverse events. QRA using fault tree analysis (FTA) is based on the assumptions that failure events have crisp probabilities and they are statistically independent. The crisp probabilities of the events are often absent, which leads to data uncertainty. However, the independence assumption leads to model uncertainty. Experts’ knowledge can be utilized to obtain unknown failure data; however, this process itself is subject to different issues such as imprecision, incompleteness, and lack of consensus. For this reason, to minimize the overall uncertainty in QRA, in addition to addressing the uncertainties in the knowledge, it is equally important to combine the opinions of multiple experts and update prior beliefs based on new evidence. In this article, a novel methodology is proposed for QRA by combining fuzzy set theory and evidence theory with Bayesian networks to describe the uncertainties, aggregate experts’ opinions, and update prior probabilities when new evidences become available. Additionally, sensitivity analysis is performed to identify the most critical events in the FTA. The effectiveness of the proposed approach has been demonstrated via application to a practical system.

Journal Article Type Article
Publication Date Oct 25, 2018
Print ISSN 1080-7039
Electronic ISSN 1549-7860
Publisher Taylor & Francis
Peer Reviewed Peer Reviewed
Pages 1-30
Institution Citation Yazdi, M., & Kabir, S. (2018). Fuzzy evidence theory and Bayesian networks for process systems risk analysis. Human and Ecological Risk Assessment, 1-30.
Keywords Risk analysis; Fault tree analysis; Process safety; Evidence theory; Fuzzy set theory; Bayesian networks; Uncertainty analysis
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