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| Criterion |  Operations 8D Problem Solving |  UX Research Affinity Diagramming |  UX Research User Interviews |  Operations 5 Whys |
|---|---|---|---|---|
Purposedifferent | For an acute quality or delivery problem, the method structures immediate protection and root cause work together. It keeps the situation stable while the actual cause is investigated cleanly. | When research notes, feedback, or observations sit unconnected side by side, affinity diagramming sorts the raw material into solid themes. Many individual points turn into patterns that make decisions and opportunities clearer. | When teams derive needs only from assumptions and real motives are missing, user interviews give direct access to behavior and meaning. Conversations from the target group's everyday life make patterns, tensions, and open questions solidly visible. | For a single, hard-to-explain deviation, the method exposes the causal chain behind the visible symptom. It keeps the cause open until a controllable condition emerges instead of a mere description. |
Complexitydifferent | High | Low | Low | Low |
Timedifferent | 1-6 Wochen | 45–90 min | 30–60 min per interview | 15-30 min |
Participantsdifferent | 4-10 | 3-10 | 1 participant per interview | 2-6 |
Formatdifferent | Workshop + async | Workshop | Workshop + async | Workshop |
Outputdifferent | 8D Report, Containment Plan, Root Cause Evidence, Corrective Action Plan | Theme clusters, Insight statements, Opportunity areas | Interview Notes, Themes, Insight Summary | Root cause notes, Countermeasures |
Tagsno overlap | QualityProblem solvingRoot cause | SynthesisQualitativeRoot cause | QualitativeResearchCustomerDiscovery | Root causeIncidentLeanProblem solving |