General Guidelines
Ask “Why” until the root cause is uncovered
May be more than 5 Whys or less than 5 Whys
If you are using words like “because” or “due to” in any box, you will likely need to move to the next Why box
If you don’t ask enough “Whys”, you may end up with a “symptom” and not “root cause”.
Corrective action for a symptom is not effective in eliminating the cause
Corrective action for a symptom is usually “detective”
Corrective action for a root cause can be “preventive”
Path should make sense when read in reverse using “therefore”