Lean Quote: Ask and Answer “Why” Five Times to Get to Real Cause of Problems

On Fridays I will post a Lean related Quote. Throughout our lifetimes many people touch our lives and leave us with words of wisdom. These can both be a source of new learning and also a point to pause and reflect upon lessons we have learned. Within Lean active learning is an important aspect on this journey because without learning we can not improve.

"The Toyota production system has been built on the practice and evolution of this scientific approach. By asking and answering ‘why’ five times, we can get to the real cause of the problem, which is often hidden behind more obvious symptoms."   — Eric Ries, The Lean Startup

I am a big believer in the 5-Whys process. The 5-Whys have withstood the test of time as a successful process for problem solving in hundreds of companies around the world.

The technique consists of the following:

Start by identifying a problem that you’re having.

Ask “why” that problem is occurring. Make sure that your answer is grounded in fact. You should be able to state the proof or evidence that you’re relying on for your assertion of the reason why the problem is occurring.

Once you have an answer, ask “why” again.

Continue the process until you reach the root cause of the problem. Usually, you’ll be able to identify the root cause of a problem after asking “why” five times.

Once you’ve identified the root cause of the problem, come up with a counter-measure that prevents it from recurring.

Here’s an example involving an individual who’s late for work:

Problem: You were driving to work and your car broke down.

First “Why?”: The battery died.

Second “Why?”: The alternator stopped functioning.

Third “Why?”: The alternator belt broke.

Fourth “Why?”: The alternator belt was well beyond its useful service life and not been replaced.

Fifth “Why?”: The vehicle was not maintained according to the recommended service schedule. (This is the root cause of the problem.)

Solution: Fix the root cause of the problem by implementing a maintenance schedule for the vehicle in accordance with the recommended service schedule.

Five Whys is effective because it is simple and can often help you get to the bottom of a problem. The simplicity is part of its genius. It is easy to learn, easy to teach, easy to understand, and easy to use. Companies are naturally complex, so the challenges they face can be complex as well. The 5 Whys helps break these problems down into manageable sections. And, while 5 Whys is designed to identify process errors, it can also be applied to business strategy as well. Its versatility and functionality make it a fantastic tool that can be applied to both process and strategy.