Compares an outlier with a stable case and filters out the differences that explain the deviation.
Core question: Which evidenced change distinguishes the event from a comparable incident-free situation, and what effect did it have?
Analysis methodMethod form: Analysis method. Describes how this method is used in practice.MediumComplexity: medium. Estimates preparation, facilitation effort, and method confidence needed.Workshop + asyncFormat: workshop or async. Shows whether the method works in a workshop, asynchronously, or both.
45-120 min
2-6
Details
EngineeringCategory: Engineering. Describes the method's domain of use.
Narrows down the fault space and symptoms step by step until only a few hypotheses and targeted tests remain.
Core question: Which smallest subsystem contains the fault when candidates are systematically excluded through discriminating tests?
Analysis methodMethod form: Analysis method. Describes how this method is used in practice.MediumComplexity: medium. Estimates preparation, facilitation effort, and method confidence needed.Workshop + asyncFormat: workshop or async. Shows whether the method works in a workshop, asynchronously, or both.
30-180 min
1-6
Details
EngineeringCategory: Engineering. Describes the method's domain of use.
Frames symptoms as hypotheses, prioritizes tests by information value, and records diagnosis and evidence.
Core question: Which competing hypothesis best explains all observed signals, and which safe test discriminates among them most strongly?
Analysis methodMethod form: Analysis method. Describes how this method is used in practice.MediumComplexity: medium. Estimates preparation, facilitation effort, and method confidence needed.Workshop + asyncFormat: workshop or async. Shows whether the method works in a workshop, asynchronously, or both.