THE "5-WHY'S" METHOD
PART OF THE LEAN MINDSET
What is the "5 Why's" Method
If a problem is happening constantly, there may be something else causing it. The “5 Whys” method helps you to figure out the root cause of a problem by asking “Why” multiple times. Think of it like a child asking “why” to everything when they are being curious. It is sometimes referred to as “going upstream” to find the root of the problem.
Example
Let’s look at an example from the toy factory. Rather than painting the wheels on the wooden cars by hand, they now use a paint sprayer.
The problem is that some of the wheels are coming out with patchy paintwork.
We could immediately blame the operator or the equipment for the defect. But the better approach is asking the “5 Whys” to get to the real root cause.
Why is the paintwork on these wheels so poor and causing defects?
Because the paint sprayer isn’t spraying evenly.
Why is the paint sprayer not spraying evenly?
Because the paint sprayer is clogged
Why is the paint sprayer clogged?
Because it hasn’t been regularly cleaned.
Why hasn’t it been cleaned regularly?
There was no maintenance schedule put in place for cleaning it.
Why was there no maintenance schedule in place?
When the paint sprayer was installed, no-one was given ownership of its maintenance.
After asking the “5 Whys”, the toy factory found that the wheels were coming out defected due to improper maintenance.
They should add a maintenance schedule and make someone responsible for the paint sprayer. In turn, this will fix the issues of defected wheels.
The “5 Whys” method can help identify root causes rather than dealing with the smaller problems caused by these issues. This itself saves time in the future.
Rather than dealing with a recurring problem each time it happens, you stop it at the root, which is far more effective. Fixing a root cause may stop other potential issues in the future too. In the example above, you may then realise that other equipment doesn’t have a maintenance schedule. Giving these other items regular maintenance could stop that equipment causing defects too.
Getting your team on board with the “5 Whys” method will encourage critical thinking. It gives people a problem-solving mindset. Rather than just fixing problems, they will think how to stop them ever happening again.
Exercise
Next time a defect or problem occurs, ask why it happened. Then ask why the previous thing happened and “go upstream” to find out the root cause.
Find an improvement for the root cause and keep an eye on whether that problem happens again.
