手法を比較

	堅牢な根本原因分析	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	1990s–2000s	1981
提唱者	Synthesised from RCA practice (Kepner-Tregoe, 1960s) and Taguchi robustness principles (1980s–1990s)	Vesely et al. (US NRC Fault Tree Handbook)
種類	Hybrid quality-engineering diagnostic method	Deductive top-down failure analysis
原典	Andersen, B., & Fagerhaug, T. (2006). Root Cause Analysis: Simplified Tools and Techniques (2nd ed.). ASQ Quality Press. ISBN: 978-0873896924	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 RCA, Robustness-Integrated Root Cause Analysis, RRCA	FTA, Fault Tree Method, Top-Down Reliability Analysis, Hata Ağacı Analizi
関連	6	3
概要	Robust Root Cause Analysis (Robust RCA) integrates classical root cause investigation techniques — such as the 5-Whys, Ishikawa diagrams, and fault trees — with Taguchi's robustness thinking to identify not only the primary cause of a failure but also the noise factors and variability sources that allow the failure to occur repeatedly. The result is corrective actions that eliminate the root cause and make the system inherently insensitive to future variation.	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.