Begin with a cause worth testing
In EasyFixProblem, a Why-Why branch begins with a Fishbone cause. If the observed problem is an unexpected conveyor stop, one branch might investigate the recorded motor overload trip. Check the event log before treating the trip as the cause rather than a symptom.
Ask questions that evidence can answer
For example: Why did the drive trip? Was the load above its operating range? What did the trend and inspection records show? Depending on the answers, the investigation might branch toward a mechanical issue, a process condition or a faulty measurement. Those are example questions, not findings about a real machine.
Write down what is known and what is still uncertain. The existing verdicts are Unverified, True, False, Inconclusive and Root Cause. A case may have multiple Root Cause nodes; marking one does not erase another.
Stop when the team can act and verify
A plausible explanation alone is not enough. Validate each candidate against evidence and consider whether correcting it would prevent recurrence. Turn validated causes into corrective or preventive actions, assign ownership and check effectiveness after the work is done.
A branching record beats a neat chain
Industrial failures rarely follow one tidy line. Keep parallel branches when evidence points in different directions. A rejected answer remains part of the reasoning, while an incomplete branch stays visibly incomplete rather than being presented as a finished conclusion.