After the elaborate piece on the Cause and Effect diagram we will take a deeper look in the 5 Whys as a root cause methodology.

The concept behind 5 why’s is that you keep on asking the question why did it happen until you reached to the underlying cause. Due to this setup the 5 Whys methodology is a very power tool for the root cause analysis because it forces people to really think about what went wrong.

Example

A wrong product has been delivered by a supplier.

1 Why. Why was a wrong product delivered?

The purchase department provided the wrong information.

2 Why. Why did the purchase department provided the wrong info?

The found this info on the server which they assumed was the latest version.

3 Why. Why wasn’t the latest version on the server?

Sales had been negotiating with the customer and forget to update.

The analysis shows that something went wrong in the process. Modifying the process can prevent this from happening in the future. A possible solution could be adding an addition step in which purchase just cross check with sales before they purchase the goods.

Also in this example it is clear we didn’t reached till the fifth why. This is not important sometimes the root cause is clear after 3 steps sometimes after 5. But for sure the root cause is clear after 5 steps.

Boundaries

When it comes to 5 Whys there are not so many boundaries. The strong characteristic about 5 Whys is that it allows you to find a root cause within purchase while the issue occurred at sales. This broad and inter process root cause analysis can very effective because of characteristic.

However, with the 5 Whys it is very easy to reach a level where it is easy to just blame a person or department. It is important to leave the personal aspects out of the equation and focus on the processes and organisation. Blaming somebody doesn’t help, always try to look at the organisation. So when a particular person is making the same mistake multiple times maybe we should give him or her training to improve his way of working. Or maybe the recruitment process is not how it should be. Just try to prevent blaming people.