5 Why Analysis and The Butterfly Effect

5 Why Analysis and The Butterfly Effect

I recently had a conversation with a Japanese colleague and he shared with me a proverb from his home country that I think it’s worth sharing.  It dates back to the edo period (1603 to 1868) so some of the references are to very old customs.

When the wind blows, woodstores (carpenters) make money.

When the wind blows, sand blows into the air

When there is sand blown into the air, it gets into people’s eyes

When people get sand in their eyes, they go blind

More blind people means more guitar sales ( because blind people in the culture and era played guitar called Shami-sen)

More guitars being made means less cats (because Shami-sen were made of cat skin)

Less cats means more mice

Mice will gnaw holes in wooden buckets that carry water

When the buckets have holes in them, the woodstores sell more buckets

When woodstores sell buckets, they make money

The nature of this story makes me think of something known as The Butterfly Effect.  This is a theory that was introduced by a MIT meteorologist named Edward Lorenz in a paper he wrote in 1972.  He formed the idea as a result of some changes he made to a meteorology computer simulation program.  As he ran his simulation and the program predicted a particular weather pattern, he changed one of the numbers from .506127 to .506 resulting in a completely different weather prediction, even though the change of the input was extremely subtle.  This inspired Mr. Lorenze to pose the question: can something as subtle as the flapping of a butterfly’s wings create a chain reaction in the atmosphere that can eventually result in influencing a major weather event, like a tornado or hurricane, on the other side of the world?

As in the case of the woodstore making money, the chain reaction set in place by the wind led to several other events, ultimately ending in the woodstore making money.  Perhaps the wind that caused the sand to blow was caused by a butterfly flapping its wings.

In the Lean world, we commonly investigate problems by backtracking the trail of events in order to understand  the root cause.  When a true root cause of a problem is identified, you can implement a countermeasure to stop the root cause from occurring again, thereby eliminating the problem from reoccurring.  We call this a 5 Why technique because it is believed that it takes 5 steps of backtracking to get to the root of the problem.

I would like to make a few points about the 5 Why technique that I commonly see companies get wrong.

  1. The point is to trace the cause back to a point that you can control. After all, it doesn’t make much sense to literally determine that a butterfly’s wing beat caused a defect in your process.
  2. The practice is to ask why in order to get to the cause, you should not determine your opinion of the cause and try to force a 5 Why analysis to fit your opinion.
  3. You may end up with several branches of 5 Why threads for one issue. Your analysis may end up looking similar to the roots of a weed.
  4. Some people think that it’s too time consuming to do 5 Why analysis. This is only true in the short term.  If you don’t have time to do it right, you must have time to do it again.

The very fact that you are reading this post right now is due to a series of events that brought you to this point and the future will be determined by all of the chain reactions of events.  In a Lean facility we aim to reduce waste and you can only do that if you understand what causes it.  Make sure you are practicing your 5 Why activity and you will be successful in solving your problems.

Please like & share:

Related Posts


  1. B.W. Robinson
    February 16, 2015 09:00 Reply

    I was fortunate to work with a lean expert that taught me the 5 whys and I was able to use them last week to get to the root cause. I was approached by a person in production regarding a tube bending machine we have, and here’s how it played out.

    1) What’s the problem? “they’re inconsistent, so we have to do additional work (defect) to meet quality standards”.
    2) Why do you feel they’re inconsistent? “because the table the tube travels on is out of square and it’s loose”.
    3) Why is it out of square? “the structure isn’t beefy enough. When it rotates with the bend, the hinges get loose and it drops”.
    4) Why does the table rotate with the machine? “because it needs to”.
    5) Why does it need to? “I think there would be clearance issues”.
    6) Why would there be clearance issues? (no response)

    I’m currently building a stationary table that will solve a problem they’ve been dealing with for years, yes, years. The team was so engaged at this point that we came up with ideas to make the workspace more efficient and they eliminated 2 processes.

    B.W. Robinson

Leave a reply