The Five "Why's" to Finding Root Cause

In the manufacturing world, I learned a very important technique to reach the root cause of any problem.  It's called the 5 why's. The 5 Whys is a question asking technique used to determine the root cause of a problem. The 5 in the title suggests it should take no more than 5 questions to get to the root cause of the problem. Developed by the founder of Toyota Sakichi Toyoda, the 5 Whys Technique is used in problem solving, trouble shooting and improving processes. Here’s how to use the 5 Whys Technique.

Start with the problem and ask a ‘why’ question about the problem. The next ‘why’ question you ask should then follow on from the answer to the first question. Here’s an example:

The vehicle will not start. (the problem)

Why? – The battery is dead. (first why)
Why? – The alternator is not functioning. (second why)
Why? – The alternator belt has broken. (third why)
Why? – The alternator belt was well beyond its useful service life and not replaced. (fourth why)
Why? – The vehicle was not maintained according to the recommended service schedule. (fifth why, a root cause)
You could possibly take this to a 6th or 7th why, but 5 is usually enough to get to the root of the problem.

It’s important to understand that typically the 5th why doesn’t point to a solution – it points to processes. This answer doesn’t tell you how to fix the problem, only what caused it.

I recently challenges the account managers to pick the top 3 safety concerns and then present actions we can take to mitigate them.  Using this method, but replacing the "why" with other questions is another effective way to use repeated questioning to draw out good ideas. The key is the drill down.  Other words to use instead of "why" are: how, what, who, what, when.  

"Why don't our people where seat belts?" 
"How can we stress the importance of seat belt use?" 
"What are the various ways we can roll out such a campaign?" 
"Who is going to champion this aspect of the solution?"
"When will this be done?"

So I think you get the idea - keep drilling down till you completely surround the issue.  Extract action items and assign champions and due dates.  Successful companies operate this way - finding root causes, drilling down on issues, assigning responsibility and holding each other accountable for execution.