Step 9 · Root-cause method
Root-cause analysis
Expert mode offers any of the RCA methods. Remember the separation the pack requires: the mechanism is what physically happened; the root cause is the correctable reason those conditions existed or were not controlled.
Cause-and-effect (Fishbone / Ishikawa)
5 Whys
Change / Difference Analysis
Events & Causal Factors (timeline)
Barrier Analysis
FMEA / FMECA
Fault Tree Analysis
Barrier Analysis
Identify the barriers (controls) that should have prevented, detected or mitigated the event and determine why each was absent, failed, degraded or bypassed.