手法を比較

	最適化支援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	1975 (ETA); optimization integration ~1990s–2000s	1981
提唱者	Event tree analysis originated at the U.S. Nuclear Regulatory Commission (WASH-1400, 1975); optimization integration developed through risk engineering literature from the 1990s onward	Vesely et al. (US NRC Fault Tree Handbook)
種類	Hybrid risk analysis and optimization method	Deductive top-down failure analysis
原典	Bedford, T., & Cooke, R. (2001). Probabilistic Risk Analysis: Foundations and Methods. Cambridge University Press. ISBN: 978-0521773194	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	OA-ETA, optimization-integrated ETA, optimization-enhanced event tree analysis, ETA with optimization	FTA, Fault Tree Method, Top-Down Reliability Analysis, Hata Ağacı Analizi
関連	5	3
概要	Optimization-assisted event tree analysis couples the structured probability logic of classical event tree analysis (ETA) with an optimization layer — typically mathematical programming or metaheuristic search — to identify the best combination of safety barriers, mitigation strategies, or resource allocations that minimizes risk or cost while satisfying engineering constraints. It is used in industrial risk engineering, nuclear safety, process industries, and infrastructure reliability.	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.