7 Steps to 5 Why

5 Why Analysis

John is the young Production Manager at a food manufacturing plant. John came to work this morning optimistic that today was going to be a great day. He is feeling pulled down though as he and his team are fighting a downtime issue. The filler on his highest priority line is down for another bearing failure. Fred, the seasoned Plant Manager has seen this before.  He is putting on the heat: “What’s wrong, John, didn’t this bearing go out last week too?”[tweetmeme]

John replies, “Yes, this is the same bearing. Everyone thought that it was just too old and was wore out. I guess we were wrong.”

Fred wants John and his team to learn from the experience and is not interested in placing blame: “OK, John. Let’s see what we can learn from this breakdown. What do you think we should do differently this time? We don’t want this bearing to burn us 3 times, do we?”

“No, we certainly don’t, ” says John.  “I’ll lead a 5 Why to make sure we get to the root cause this time….”

John knows that the 5 Why Root Cause Analysis is a great tool. The 5 Why will help you get to the root cause and implement effective countermeasures when done properly.

Root Cause Analysis Process

There are 7 Steps to an effective 5 Why:

  1. Problem Selection: There are plenty of issues out there.  Select one that you can focus on.  Use the Pareto Principle to make sure you get a good bang for the buck.
  2. Problem Statement: Define the problem.  Be specific.  Keep the scope small and realistic.
  3. Ask Why 5 Times & Select Countermeasures: Start with the problem statement.  Ask why it happened.  Ask why until you have found the root cause.  Asking why 5 times often gets to the root cause.  Discuss and select the countermeasures that will ensure you don’t have this problem again.  Addressing the true root causes prevents or at least minimizes the problem.
  4. Implement Countermeasures: Communicate the changes to everyone who needs to know.  One Point Lessons are often good for this purpose.  Don’t forget the night-shifts and other departments.
  5. Analyze Effectiveness: Review the results of the new procedures.  Modify the countermeasures if needed.   You may even need to try something completely different if the countermeasures are not effective.  In this case, you should also ask yourself if you really got to the root cause.
  6. Standardize: Update your SOP’s to reflect the new procedures.  Update training plans for new operators.  Ensure that everyone who needs to know is in the loop.  Ask yourself if there are other areas to apply the new knowledge.  You may have another production line with the same equipment that could use the same improvement.
  7. Check & Control: Implement systems to insure the new procedures are followed and are effective.  Follow up.

John and his team have finished their 5 Why on this bearing failure.  They discover that a new operator is not lubricating the bearing properly.  The team develops a One Point Lesson and is able to make it part of the training for new hires.[tweetmeme]

What about you and your team?  Do you have repeat issues that you need to resolve?  The 5 Why Root Cause Analysis (RCA) will help you find and address the root causes.


Not all RCA’s are the same in the real world.  In reality, one Root Cause Analysis may be quite simple, but many are more complex and require a multiple path solution.  I’ve written follow-up articles illustrating each.  Click on these hyperlinks to see a Simple 5 Why and Complex 5 Why.

Please leave a comment below if you liked this article. You can also connect on LinkedIn, follow me on Twitter, subscribe via e-mail (right side bar), retweet, digg, or stumble this article. Your feedback is appreciated.

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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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32 Responses to 7 Steps to 5 Why

  1. Very thorough advice. I can see how this would result in substantial improvements!

  2. A new meaning for take 5. Sounds like a very reasonable and efficient strategy. I’ll have to give it a try.


  3. I have found that the majority of the information out there as it pertains to 5Y is a bit flawed. In this example…the bearing that has failed, first step states to pick a problem. I am assuming that the failed bearing is the problem, but it informs you that there are many problems out there and to use a pareto to pick the best one.

    So failed bearing…Why? Why did it fail? The first why you ask is the most important one, I guess it can relate to your problem statement. If you don’t ask the right question off the bat your whole 5Y can be derailed.

    The flaw I have found with most 5Y exorcises I see online is that they are linear, you have one answer to a Why? And it seems like we may have multiple reasons for a why but we interbnally chose the best one that fits our current situation.

    But it has been my experience that a why may have multiple answers And that is why I use a bracketed approach. This way all conceivable reasons for a why? are placed and used and the question is continued to be asked Why? After this exorcise is done…now you have a plethora of reasons why something was out of place or causing variance (problem) now you use you pareto or a ranking tool such as ICE and create a A3.

    Well just my thoughts…

    • Daniel,

      Thanks for reading and for adding to the discussion. It sounds like we share some similar experiences with the 5Y analysis. You have valid points. I avoided going into all the possibilities to keep the article from getting too long. Any Root Cause Analysis has to be done properly or you get a flawed root cause. In which case the countermeasure(s) are likely to fail. This is why I’ve added the follow up steps after the implementation of the countermeasures. The last 3 steps are similar to a PDCA (Deming Circle) or DMAIC which follow up on the effectiveness. The temptation in a busy manufacturing plant is to roll out the countermeasure and move on to the next problem assuming that the countermeasures work.

      The assumption with the linear 5 Why’s you see on line is that it’s a simple 5Y. I agree that it’s rare that these get that simple. In most cases there are multiple root causes and countermeasures. This is why the superficial responses to the issue didn’t work in the past. To me, even the simpler 5Y’s have more than one root cause. The most complete root causes have multiple reasons for each of the 5 Y’s and the analysis looks like a pyramid when you are done. I recall one RCA that I led when I was a Plant Manager at a plastics blow molding plant. We had flip charts covering 3 of the 4 walls by the time we finished. It was an extensive exercise but we completely resolved and issue that had been nagging us for months.

      Thanks again. You have great insight to the discussion.


  4. Great story Christian, this is more than a story, love it!

  5. Great example to explain the “5 Why Root Cause Analysis” tool. I have to confess, this is a new tool to me. I can see this method of getting to the root cause to be effective in many situations including process improvement. Thanks for sharing.

  6. A link to this blog was posted in the LinkedIn Kaizen Group. There were a lot of good comments there which I want to share. I’ll cut and paste those into the discussion here. Those that happen to be a member of that group can see the discussion directly by clicking http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=32774916&gid=47831&commentID=25004036&trk=view_disc .

    • From John Musster: As a SME (Subject Matter Expert) in business continuity planning, supply chain alignment and enterprise risk management (AU/ANZ 4360:2004) … I agree with Daniel.

      The 5W is to simplistic methodology to understanding the “root cause” and to manage reoccurrence of similar failure / fault.

      I find “Fault Tree Analysis” – a more effective way to get to the root case. The Operation Symbols such as “Event” and “Logic Gates” and “Transfer” – will provide you with a deeper understanding to;
      (a) The reason for the current failure, and
      (b) Likely probabilities of other factors that could have caused a similar failure … thus putting you into a better position to instigate processors/controls to mitigate against likely failure/fault.

      By taking a holistic approach to understanding the “Fault” – I believe that I am in a better position to monitor + manage the risk.

      Anyway, this is my experience.

      – HERM Logic (www.hermlogic.com)

    • From Richard Steel • Lets get this in perspective…5 Why’s were meant for everyone in the organisation to learn so they could question the status quo and it is a simple tool and should be treated as a cultural shift. There are many detailed and complicated analysis tools which you have mentioned but these are not for the fenit hearted and would put off most people, which would be a shame…
      Keep it simple…go deep when you need to… Improvement is for everyone not specialists and people that can drive minitab…

    • From Craig Cartmell • I have been practicing Kaizen since the I was trained at Toyota in Nagoya in the 1980’s, and I often wonder how it is being trained now outside of Japan. This piece and the first three comments above only add to that wondering… In short, Richard has it right.
      Kaizen most often fails when it is led by management and ‘experts’. Big Men need Big Projects and expect Big Results. To be flippant – Six Sigma was invented to keep the Big Men busy while the rest of us did Kaizen 🙂
      The 5 Why tool was created as a method for shopfloor and office workers to question each of the identified probable causes from an Ishikawa diagram.
      Note the word ‘each’ above. There is a recognition in Kaizen that a problem more often than not has a matrix of causes, some more significant than others, but each having a contribution.
      The 5 Why approach is not meant to throw up solutions or even to always bring one to the actual root cause. Instead it makes you consider the chain of circumstances that led to the effects of the problem. Many 5 Whys founder after the third Why, but some go on to 7 or more Whys. The chain of responses to a 5 why exercise may also lead you to abandon a probable cause, or to diminish its importance.
      Once you have carried out a 5 why exercise on each of the probable causes you look for points of correspondence between them. The more points a probable cause has in the 5 why chains the more likely that action in this area will contribute to the solution of the problem.
      For example you may find the same documented procedure or instruction being identified as inadequate in several of the 5 why chains. Improvement of that one document may reap benefits from several directions towards the eventual solution and elimination of the problem.
      Using 5 Whys on a single determined cause is not searching for solutions, it is simply justifying the mental prejudices of the person who chose the cause.

    • John, Richard & Craig,

      Thank you for your thoughtful comments. It’s good to see your thoughts and to hear from practitioners who have really put it to use. I agree that the real word examples are not often as easy as the example in the article. In fact, I can’t think of a singe 5 Why that was a straight line, simple 5Y with one root cause and one countermeasure. There are almost always multiple causes for one or more of the why’s. The intent of the article was to keep it simple and introduce the tool. It sounds like a follow up article is warranted. Thanks again for your insight and comments. I’m enjoying the discussion.


    • From Don Grimley • I agree with Craig. The 5 W system is for shop floor people to use. Once you get the engineers and analysis in the picture they will be the ones to use the fault tree or other systems to improve the process. If you make 5W too complicated you loose Kaizen and get back to management only lead improvement.

  7. Pingback: Simple 5 Why’s | Life's Lessons in the 21st Century

  8. ss dengle says:

    can you please give an exaple of 6w2H also.

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  10. Pingback: Complex 5 Why’s – Multiple Path Solutions | Life's Lessons in the 21st Century

  11. najemeddin says:

    I am a big fan of “asking Why method” , I am using this technique to evaluate my personal targets by asking myself “why I am doing the thing I am doing now? ” , If there is no clear answer or the answer is not connected to any of my targets , I start thinking of doing something else related to my targets to do.
    I also created a blog to remind people of their vision http://www.najmo.com , you can comment with your vision or dream and we will send you the same email each new year to remain you to keep focus on your dream.

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  13. Redge says:

    In this case the “physical” problem is known. Many 5 Why’s address the singular issue of process. I contend in many cases that a parallel 5 Why should also be conducted on the “system”.

    As mentioned in an earlier comment, I too find that many 5 why’s fail because the right questions aren’t being asked or the series of questions don’t follow. I use a top down 5 Why (deductive) and counter check with a bottom up “If Then” (inductive) analysis.

    If the event sequences do not follow, a fault exists in the 5 Why.

    I recognize that this can be an exhausting topic and appreciate the brevity of the post. Thanks for sharing.

  14. A nice lesson i would say for beginner like me, i would like to ask you 2 questions:

    1. In the 5 why technique, is it always necessary to come out with 5 why’s? I mean sometimes you might just have 3 why’s and it might be pointless have those 2 extra why

    2. Same goes for 7 ways, is it always necessary to come out with 7 of them?

    Lastly i would like to know which body gives a authentic training and certification for kaizen, its not clear to me.
    Thanks in advance 🙂

    • Hello Saurabh,

      Good questions. You will not always get 5 why’s when using this technique. The idea is to keep asking why until you get to the root cause. Some situations don’t have 5 why’s and some have more. Different situations will require digging deeper. You could also skip or add to the process depending on how the why’s are answered. It’s most important to be sure you got to a root cause and not a surface symptom. As for the 7 ways, I presume you are asking about the 7 steps in the article. These steps are important from experience. Someone might have another step or two to add or might combine some of the steps but these are the basics that should work if followed. The follow-up (steps 5-7) are critical and often overlooked. The changes are not as likely to take hold if the follow-up is not there. I hope this helps.

      You might also want to read a couple examples: http://wp.me/pZiRD-li and http://wp.me/pZiRD-lM

      Best regards,

  15. Redge says:

    Nice post Chris. I address both process and system – using a 5-Why for each – or even a Why made, Why shipped analysis.

    A great tool if it is used correctly and that includes starting with the right premise and question series. Often times a team may think they have identified the root cause even before the 5-Why analysis. As a result, the questions are tailored to support their assumptions.

    I also recommend a reverse read from the root cause to the problem statement. Because of “A”, therefore “B”, therefore … “We had this problem”.

    Thanks for sharing!

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  18. Bill Wilson says:

    Hello Christian,
    I know this reply is coming to you several years late, but that should be alright because I’m going to point you to a blog article of mine that predates yours by about 5 years. 🙂


    In short… I proposed something that I dubbed 5×5 Whys. The aim was to inject a little rigour into the regular 5 Why process (causal testing for existence, necessity, sufficiency) and perhaps pave the way towards more robust, multi cause analysis methods.

    Liking your blog, by the way!

    Bill Wilson

    • Bill,

      Thank you for sharing your insight and a link to 5×5 Why’s. I enjoyed your post there and left a comment as well. Your 5 questions are good and can be used to validate the root causes. Thanks for reading this blog and for sharing your insight.


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