Who this is for: Needs Manage Root Cause.
Fault Tree Analysis is the right choice for complex failures with several interacting causes — typically major nonconformities, or anything where more than one control had to fail for the problem to occur.
State the Top Event (Failure being analysed) — the finding, expressed as what went wrong.
Record the Contributing Cause entries that directly led to it. Up to four are provided.
For each branch, work downward to basic, actionable causes.
Choose a root cause category and save.
Work top-down and be honest about the branches. The point of the method is that it surfaces the causes that had to combine — if you only record one branch, use 5 Whys instead and save yourself the effort.
Once you have filled in the method, Root Cause Category becomes required. See 7.9.
Whether Fault Tree Analysis is available is set in Audit Settings → Records & Findings.
Related: 7.6 5 Whys · 7.7 Fishbone · 7.9 Selecting a root cause category