手法を比較

	Semi-Quantitative Risk Matrix Analysis	Bow-Tie Risk Analysis
分野	Disaster Studies	Disaster Studies
系統	Process / pipeline	Process / pipeline
提唱年	2019	2016
提唱者	ISO/IEC 31010 (standardized practice); critical analysis by L. A. Cox	Synthesized review by de Ruijter & Guldenmund; standardized in ISO/IEC 31010
種類	Semi-quantitative consequence-likelihood rating and ranking pipeline	Barrier-centred cause-consequence risk diagram and analysis
原典	International Organization for Standardization. (2019). IEC 31010:2019 Risk management — Risk assessment techniques. ISO/IEC, Geneva.	de Ruijter, A., & Guldenmund, F. (2016). The bowtie method: A review. Safety Science, 88, 211-218.
別名	Risk Matrix Analysis, Consequence-Likelihood Matrix, Probability-Impact Matrix, Risk Rating Matrix	Bowtie Method, Bow-Tie Diagram, Barrier Analysis (Bow-Tie), Cause-Consequence Barrier Model
関連	3	3
概要	Semi-quantitative risk matrix analysis rates each risk on ordinal likelihood and consequence scales and combines the two in a grid to assign a risk level that drives prioritization. It is the workhorse of practical risk management: ISO/IEC 31010 lists the consequence-likelihood matrix among its standard techniques precisely because it lets analysts compare many disparate risks quickly without the data demands of a full quantitative model. The 'semi-quantitative' label captures its hybrid character — ordinal categories such as 'rare' or 'catastrophic' are anchored to rough numeric bands, giving more discipline than a purely verbal judgment but far less than a probabilistic calculation. The method's popularity is matched by sharp critique: L. A. Cox's 2008 analysis in Risk Analysis showed that poorly designed matrices can rank risks incorrectly, compress very different risks into the same cell, and even perform worse than random, making careful scale design and consistency checks essential rather than optional.	Bow-tie risk analysis is a barrier-centred technique that places a single top event — the moment control over a hazard is lost — at the knot of a diagram, branches its possible causes to the left and its possible consequences to the right, and arrays along each pathway the barriers meant to prevent or mitigate it. The shape gives the method its name: the fanning threats and consequences form the two halves of a bow tie around the central event. de Ruijter and Guldenmund's 2016 review in Safety Science documents how the approach grew popular precisely because it combines, in one readable picture, the cause logic of a fault tree and the consequence logic of an event tree while foregrounding the controls that managers actually own. ISO/IEC 31010 lists bow-tie analysis among standard risk-assessment techniques, used both qualitatively to communicate risk and barrier coverage and quantitatively to estimate consequence likelihoods.