手法を比較

	リスクベース故障木解析	リスクベース信頼性解析
分野	実験計画法	実験計画法
系統	Process / pipeline	Process / pipeline
提唱年	1961 (FTA origin); risk-based integration formalised 1975–1981	1960s–1990s (risk-informed frameworks codified ~1980s–1990s)
提唱者	H.A. Watson (Bell Labs) and developed further by Boeing/U.S. Air Force; risk-based extension via NRC probabilistic risk assessment programs	Multiple contributors; formalized in reliability engineering literature from the 1960s onward (MIL-HDBK-217, IEC 60300 series)
種類	Quantitative safety and reliability analysis	Quantitative / semi-quantitative engineering analysis
原典	Vesely, W. E., Goldberg, F. F., Roberts, N. H., & Haasl, D. F. (1981). Fault Tree Handbook. U.S. Nuclear Regulatory Commission, NUREG-0492.	Modarres, M., Kaminskiy, M., & Krivtsov, V. (2006). Reliability Engineering and Risk Analysis: A Practical Guide (2nd ed.). CRC Press. ISBN: 978-0849392016
別名	RB-FTA, risk-informed FTA, quantitative fault tree analysis, probabilistic fault tree analysis	RBRA, risk-informed reliability analysis, risk-based dependability analysis, probabilistic risk and reliability assessment
関連	6	6
概要	Risk-based fault tree analysis (RB-FTA) combines classical fault tree analysis with explicit quantitative risk assessment. Starting from an undesired top event, the analyst decomposes it into contributing causes using AND/OR logic gates, assigns failure probabilities to basic events from reliability databases or historical data, and then propagates those probabilities through the tree to compute top-event likelihood. The result is expressed as risk — probability weighted by consequence severity — enabling prioritisation of safety interventions by their actual risk reduction impact.	Risk-based reliability analysis (RBRA) is an engineering methodology that combines classical reliability analysis — quantifying failure rates, component lifetimes, and system dependability — with risk assessment frameworks that weigh the severity and consequences of each failure mode. By ranking failures according to both their likelihood and their impact, RBRA guides engineers in allocating inspection, maintenance, and redesign resources where they matter most, rather than treating all potential failures as equally important.