Simple 5 Why’s

Recharging a dead battery, Seattle, Washington...

Image by Wonderlane via Flickr

[tweetmeme]It’s a cold and rainy night in late October. You hurry out to your car in an effort to keep dry and because you are running late. You are not too wet as you get in and put your key in the ignition. You turn the key and can’t believe it: “Oh no-Not now!” Your battery is dead…..

My recent blog titled 7 Steps to 5 Why led to an interesting discussion around the application of the 5 Why Root Cause Analysis.  Several readers who have real world experience with this method contributed to the debate.  Daniel Reynoso started the discussion with several insightful comments.  One of Daniel’s points is that most on-line 5 Why models are straight line or Simple 5-Why’s.  His experience is that most real life examples are not that simple.  Daniel is right.  Many issues have multiple reasons for the failure.  These lead to more complex Multiple Path 5-Why’s.  We’ll look at the Multiple Path 5-Why’s soon enough.  Today we’ll look closer at the Simple 5-Why using the example of the dead car battery:

5 Why Analysis

Problem Statement:  My car won’t start.

Why 1:  Why won’t my car start?

Answer:  The battery is dead.

Why 2:  Why is the battery dead?

Answer:  The alternator did not charge the battery.

Why 3:  Why didn’t the alternator charge the battery?

Answer:  The alternator belt was slipping.

Why 4:  Why is the belt slipping?

Answer:  The belt is worn.

Why 5:  Why is the belt worn?

Answer:  The owner did not have the belts replaced as scheduled.

Why 6:  Why didn’t the operator have the belts replaced?

Answer:  The owner was unaware of the maintenance schedule.

Countermeasure:  The owner will read the owner’s manual to become familiar with the recommended maintenance.  The owner will also refer to the manual every 10,000 miles.

[tweetmeme]This is an example of a simple 5-Why which has a single assignable root cause.  Note that some troubleshooting and examination of broken parts will aid in the 5 Why Analysis when the 5-Why involves machinery.  There will be times where you get to the root cause in less than 5-Why’s.  There will also be times where you need to ask why more than 5 times.

Not all 5 Whys are this straight forward.  We’ll look at a multiple path 5 Why next time.


The car battery example was borrowed from Wikipedia then modified.

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About Christian Paulsen

Christian Paulsen is an Executive Consultant with 20 years of Lean Manufacturing. Chris adds value to organizations by driving process improvement and bottom line savings. Chris intends to help others by sharing the lessons learned after a quarter century of operational leadership, marriage, parenting, and even longer as a Cubs fan. Your comments on this blog are welcome. You can also connect with Chris via LinnkedIn, Twitter, and Facebook in the right sidebar. Chris welcomes your comments. Christian's professional services are available by contacting him through LinkedIn (right side bar)
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6 Responses to Simple 5 Why’s

  1. Isaac Duke says:

    Excellent! I like how your Lean approaches eliminate blame as blame is wasteful.

  2. Tim McMahon says:

    I think an important idea you subtly included in this post is the not to count the 5 why’s. It isn’t about 5 but rather a process of getting to the root cause.

    Don’t count the why’s, get to the root cause.

  3. I believe the most effective people think in this manner at all times. Blame is a lazy behavior that wastes time. Get to the root cause, come up with a plan to avoid this happening again, and move on or stagnate.

  4. Remi Banjo says:

    I love this article, it actually made me remember the last time I had a flat battery, and yes it was raining too!

    You made a valid point, it definitely is not “why is this happening”, but rather, “what made this happen”.

  5. Very direct way to problem solve Christian. I’ll look forward to reading your ” multiple path 5 Why” next time.

  6. Pingback: What’s a Fishbone Diagram? « Christian Micro-Entrepreneurs

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