What is Five Why for root cause investigation

O'PEEP'S 5 WHY'S EXPLANATION

"Why are you not drinking coffee?"
"Because I could not make coffee."

"Why couldn’t you make coffee?"
"Because there is no coffee powder."

"Why isn’t there any coffee powder?"
"Because nobody bought new coffee powder!"

"Why didn’t anybody buy new coffee?"
"Because nobody knew we had to buy coffee."

"Why was it not clear we needed coffee?"
"Because we have no system that shows what’s needed!"

5 Why (5W) is a questioning technique for identifying the root cause of a problem. Very often a superficial answer is obtained when asking why something is wrong. With this technique, “why” is asked at least 5 times so we get to the core of the problem with a logical explanation chain.

EXAMPLE

In this example, we cannot implement a long term solution if we are satisfied with the first answer. Sure we can unclog the filter but if still nobody takes care of it we will have the same problem in the future. Five Whys helped us find out that the true cause of the problem is the lack of oversight.

5 Why

CAPABILITIES DON’T GROW ON TREES

EXAMPLE