手法を比較

	ロバスト イベントツリー解析	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	1960s (ETA); robust extensions ~1990s–2000s	1981
提唱者	H.E. Lambert / Nuclear industry (ETA); robust extensions developed through aerospace and nuclear risk research	Vesely et al. (US NRC Fault Tree Handbook)
種類	Probabilistic risk assessment with uncertainty propagation	Deductive top-down failure analysis
原典	Bedford, T., & Cooke, R. M. (2001). Probabilistic Risk Analysis: Foundations and Methods. Cambridge University Press. ISBN: 9780521773201	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	Robust ETA, uncertainty-aware event tree analysis, ETA with uncertainty quantification, robust probabilistic event tree	FTA, Fault Tree Method, Top-Down Reliability Analysis, Hata Ağacı Analizi
関連	6	3
概要	Robust Event Tree Analysis (Robust ETA) extends classical event tree analysis by explicitly accounting for uncertainty in the probability estimates assigned to each branch. Rather than treating branch probabilities as precise point values, the robust approach represents them as intervals, probability distributions, or imprecise probabilities, then propagates that uncertainty through the tree to produce outcome frequency ranges instead of single numbers. This gives decision-makers a clearer picture of the confidence in risk estimates under realistic conditions of incomplete or conflicting information.	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.