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| Criterion |  UX Research User Interviews |  Decision Making Assumption Surfacing |  Operations 8D Problem Solving |  Operations 5 Whys |
|---|---|---|---|---|
Purposedifferent | 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. | Plans often contain assumptions that were never openly stated and remain dangerous precisely because of that. Assumption Surfacing makes these silent premises visible and prioritizes which of them carry the initiative or could sink it. | 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. | 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 | Low | Low | High | Low |
Timedifferent | 30–60 min per interview | 45-90 min | 1-6 Wochen | 15-30 min |
Participantsdifferent | 1 participant per interview | 2-8 | 4-10 | 2-6 |
Formatdifferent | Workshop + async | Workshop + async | Workshop + async | Workshop |
Outputdifferent | Interview Notes, Themes, Insight Summary | Assumption List, Critical Assumptions, Learning Plan | 8D Report, Containment Plan, Root Cause Evidence, Corrective Action Plan | Root cause notes, Countermeasures |
Tagsno overlap | QualitativeResearchCustomerDiscovery | AssumptionsRiskDecisionDiscovery | QualityProblem solvingRoot cause | Root causeIncidentLeanProblem solving |