Fault Tree Analysis Including Component Dependencies

Abstract

Fault Tree (FT) analysis is not only the most common technique used in engineering practice for the estimation of system reliability, but is also a key tool shared between designers, analysts, and regulators for the safe operation and licensing purposes. In spite of its long lasting success, traditional FT analysis presents significant limitations in modeling a wide range of features frequently encountered in modern systems. The most critical of these is the assumption of failure events independence, which is often not justified by the realistic behavior of the engineering system, undermining modeling accuracy. This article introduces a novel methodology for the analysis of FTs allowing for component dependencies and dynamic features. The proposed approach, based on the use of binary decision diagrams, is demonstrated using a simple numerical application for verification. Its applicability and computational feasibility is discussed in details.