Introducing the 5 Why “So What” Test

We, over at Gemba Academy, are busy finishing up our 8 Step Practical Problem Solving course which is modeled after the Toyota Business Practice (TBP) methodology.

In one of the modules we’re exploring 5 Why Analysis in more detail since we’ve learned that many people think they know how 5 Why works… but often fail to come to the results they desire.

We’re teaching our students many “techniques” often left out of this important problem solving approach including something we call the “so what” test.   Some also refer to this as the “therefore” test.

Here’s how it works.

The Milk is Spoiled

Let’s say the “problem” we’re investigating is the fact the milk in the refrigerator has spoiled… a simple example most people have experienced at one time in their life (hopefully you smelled the milk before you drank it… but I digress).

So, the 5 Why analysis (5 is just a number…  sometimes you’ll need to ask more whys and sometimes you’ll need to ask less) might go like this.

1. Why did the milk spoil?

It was left in the fridge for too long.

2. Why was it left in the fridge for too long?

We didn’t drink it fast enough.

3. Why didn’t we drink it fast enough?

We had more milk cartons than we needed.

4. Why did we have more milk cartons than we needed?

We bought more milk cartons than we needed the last time we went shopping.

5. Why did we buy more milk cartons than we needed the last time we went shopping?

There was a sale on milk and we tried to save money.

Ask So

Once you are done with your 5 Why analysis there is still an important, yet often left out, step.

Namely, we must add the word “so” at the end of the each response while then working back to the top to make sure it all makes sense.  Let’s see how this works with our example.

There was a sale on milk and we tried to save money…

so

We bought more milk cartons than we needed the last time we went shopping…

so

We had more milk cartons than we needed…

so

We didn’t drink it fast enough…

so

It was left in the fridge for too long…

so

The milk spoiled.

Simple But Powerful

While this may seem like a simple exercise I promise you there will be times when the “cause and effect” relationship of your 5 Why analysis makes no sense after adding the word “so” to the end of the statement and working backwards.

When this is the case, making the necessary adjustments will make your 5 Why analysis far more accurate and powerful.

How Do You Do This?

Have you ever used this method before?  Or, do you have another method to check the cause and effect relationship of your 5 Why analysis?

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