手法を比較

	ベイズ的故障モード影響解析 (Bayesian Failure Mode and Effects Analysis)	フォールトツリー解析 (FTA)
分野	実験計画法	信頼性
系統	Process / pipeline	Process / pipeline
提唱年	1990s–2000s	1981
提唱者	Extension of classical FMEA (MIL-STD-1629, 1974) with Bayesian inference formalised in reliability literature from the 1990s onward	Vesely et al. (US NRC Fault Tree Handbook)
種類	Probabilistic reliability and risk analysis	Deductive top-down failure analysis
原典	Bowles, J. B., & Peláez, C. E. (1995). Fuzzy logic prioritization of failures in a system failure mode, effects and criticality analysis. Reliability Engineering and System Safety, 50(2), 203–213.	Vesely, W. E., Goldberg, F. F., Roberts, N. H., & Haasl, D. F. (1981). Fault Tree Handbook (NUREG-0492). U.S. Nuclear Regulatory Commission.
別名	Bayesian FMEA, probabilistic FMEA, B-FMEA, Bayesian risk priority analysis	FTA, Fault Tree Method, Top-Down Reliability Analysis, Hata Ağacı Analizi
関連	5	3
概要	Bayesian FMEA extends the classical Failure Mode and Effects Analysis framework by replacing fixed point-estimate risk scores with probability distributions, allowing prior engineering knowledge and observed failure data to be formally combined through Bayes' theorem. The result is a probabilistic Risk Priority Number (RPN) that reflects uncertainty in severity, occurrence, and detectability ratings rather than masking it with single consensus values.	Fault Tree Analysis (FTA) is a top-down, deductive reliability method that begins with an undesired top-level failure event and systematically traces backward through chains of contributing causes using Boolean logic gates (AND, OR). First formalized by Watson at Bell Telephone Laboratories in 1961 and later standardized by Vesely, Goldberg, Roberts, and Haasl in the landmark 1981 NRC Fault Tree Handbook, FTA has become a cornerstone of quantitative risk assessment in nuclear, aerospace, and industrial safety engineering.