View methods side by side.
Choose up to four methods. Add them using the search and share the comparison by copying its link.
| Criterion | ![]() UX Research User Interviews | ![]() Operations Fault Tree Analysis | ![]() Operations 8D Problem Solving | ![]() Operations Root Cause Analysis |
|---|---|---|---|---|
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. | For a critical top event with several possible triggers, the method logically models failure paths. It makes visible which combinations of conditions can lead to damage. | 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 a problem keeps recurring and the cause stays unclear, the method exposes the underlying mechanism. It separates symptom, guess, and robust explanation from one another. |
Complexitydifferent | Low | High | High | Medium |
Timedifferent | 30–60 min per interview | 2-6 h | 1-6 Wochen | 1-4 h |
Participantsdifferent | 1 participant per interview | 3-8 | 4-10 | 3-8 |
Formatsame | Workshop + async | Workshop + async | Workshop + async | Workshop + async |
Outputdifferent | Interview Notes, Themes, Insight Summary | Fault Tree, Critical Paths, Cause Hypotheses, Control Actions | 8D Report, Containment Plan, Root Cause Evidence, Corrective Action Plan | Problem Statement, Cause Hypotheses, Confirmed Causes, Action Plan |
Tagsno overlap | QualitativeResearchCustomerDiscovery | RiskRoot causeSafety | QualityProblem solvingRoot cause | Root causeProblem solvingQualityIncident |



