October 7, 2020 | Mark Paradies

5-Why Examples [The Best and The Worst!]

5-Why Examples

5-Why Examples

Best 5-Why Examples: Below are six 5-Why examples. Please rank them from best to worst (The Good, The Bad, and The Ugly!)

I’ve been asked by many … “What do you think of 5-Whys?” Please help me answer that question. Your opinions of the 5-Whys in the comments below will help everyone judge the effectiveness of 5-Whys.

Please start by rating each example as:

  • GOOD – It really finds a root cause,
  • BAD – It doesn’t find a root cause, or
  • WORST! – is this a joke?

Please note that these aren’t 5-Why examples that I developed. These examples were posted online as good 5-Why examples (except for the joke).

One of these examples is obviously bad, but the people who posted it thought it was a good 5-Why example.

At least one is a joke. (Let’s call that it UGLY. Then we will have The Good, The Bad, and The Ugly!)

Please review ALL the examples AND VOTE by making comments in the comments section at the end of the article.

The Good, The Bad, and The Ugly

5-Why Examples: Taicchi Ohno

#1 – Taiichi Ohno, the creator of the 5-Why technique, is quoted using the following example to teach using 5-Why’s for root cause analysis:

  1. “Why did the robot stop?”
    The circuit has overloaded, causing a fuse to blow. 
  2. “Why is the circuit overloaded?”
    There was insufficient lubrication on the bearings, so they locked up.
  3. “Why was there insufficient lubrication on the bearings?”
    The oil pump on the robot is not circulating sufficient oil. 
  4. “Why is the pump not circulating sufficient oil?”
    The pump intake is clogged with metal shavings. 
  5. “Why is the intake clogged with metal shavings?”
    Because there is no filter on the pump.

What do you think?

Is “NO FILTER ON THE PUMP” a root cause?

#2 – From a medical website 5-Why example – A patient had the wrong leg amputated:

  1.  Why was the wrong leg amputated?
    The Doctor could not see the marking and thought it was the wrong leg that was marked.
  2. Why?
    The patient gave consent the night before the surgery to a registrar who does not perform the surgery and was not familiar with the patient. They marked the leg a washable marking in the wrong place.
  3. Why?
    They didn’t know about using a waterproof marking tool and were unaware of how the marking was to be completed.
  4. Why?
    They were new, and the department didn’t have a formal induction process for new registrars.
  5. Why
    No one ever said they should have an induction process. 

What do you think?

Is “No one ever said they should have an induction process.” a root cause?

#3 – Administrative example from a website explaining how to use 5-Whys – Employees did not receive pay stubs on payday.

  1. Why did employees not receive pay stubs on payday?
    Because the printing system failed the day before payday.
  2. Why?
    Because the system could not recover from a hardware fault.
  3. Why?
    Because the system uses outdated hardware that has no automatic redundant backup. 
  4. Why?
    Because the system hasn’t been replaced as it hasn’t been identified as a high enough priority to allocate budget to its replacement in the current economic climate.
  5. Why?
    Because the organization does not have an enterprise planning methodology that weighs the risks of current operational systems failing versus the criticality of these systems and the impact of such a failure. 

What do you think?

Is “Because the organization does not have an enterprise planning methodology that weighs the risks of current operational systems failing versus the criticality of these systems and the impact of such a failure.” a root cause?

#4 – According to ASQ Quality Progress, this is a good 5-Why example: Jefferson Monument is deteriorating faster:

  1. Why does the memorial deteriorate faster?
    Because it gets washed more frequently.
  2. Why is it washed more frequently?
    Because it receives more bird droppings.
  3. Why are there more bird droppings?
    Because more birds are attracted to the monument.
  4. Why are more birds attracted to the monument?
    Because there are more fat spiders in and around the monument.
  5. Why are there more spiders in and around the monument?
    Because there are more tiny insects flying in and around the monument during evening hours.
  6. Why are there more insects?
    Because the monument’s illumination attracts more insects.

Yes … I know that’s six Whys. But that is OK.

What do you think?

Is “Because the monument’s illumination attracts more insects.” a root cause?

By the way, here is a link to an article that debunks this example:


#5 – A 5-Why from Vooza, a comic site about web startups – in a video: “Why did the server crash?”

What do you think?

Is “The Illuminati” a root cause?

And yes, that was 15 Whys. Sometimes it just takes more! (I’ve seen 17 whys.)

#6 – A 5-Why example – Why root cause analysis fails:

  1. Why are people searching for root cause analysis on the internet?
    Answer: Because there is no database to search in on their computer, and the boss wants training answers now.
  2. Why is there no database on the computer to search from?
    Answer: Because these are computers produced in 2000 and a knowledge database cannot be installed.
  3. Why don’t we have new computers that can have databases installed?
    Answer the company is short on money.
  4. Why is there no money left to purchase computers?
    Answer: Because we have lost money on repeat incidents.
  5. Why do we have repeat incidents?
    Answer: Because we haven’t sent people to TapRooT® Root Cause Analysis Training.

Yes – failure to have TapRooT® Training IS A ROOT CAUSE of poor root cause analysis!

What do you think of these 5-Why examples? Leave a Comment!

Leave your comments below…

(PS: I’ve had several people e-mail me to ask how the 5-Why examples above would compare to TapRooT® Root Cause Analysis. See the comparison of Example 1 to a TapRooT® Root Cause Analysis here…

Root Cause Analysis, Root Cause Analysis Tips
Show Comments

28 Replies to “5-Why Examples [The Best and The Worst!]”

  • Mark Paradies says:

    Leave your vote as a comment.

    • Geni Chariker says:

      The 5 why’s are like the 10 Commandments – useful as an idea but definitely not nuanced or comprehensive. You only ask why while you are still in the realm of what you can control and at a practical remedial step. To do other than that is amateurish practice.

      It is like the old George Carlin bit in which he discerns that “mother’s milk” is the “gateway substance” to heroin.

    • Trevor Kavanagh says:

      With the information given I like the not getting paid root cause.

      Additionally, I think we should do a 5why on why Taproot doesn’t have “Illuminati” as an option for a root cause.

  • Mark Paradies says:

    I didn’t find any of these “good” at finding root causes – even the one by the expert – Taiichi Ohno.

    • Mike Hobbs says:

      I agree, I’m more concerned about why and where the was metal particles in the lubricant. The addition of the filter is a good protective, but better to stop the initiating cause.

      • Dan Kittleson says:

        Great points. Ohno did fix his issue permanently though that same day by using a filter. How quickly could he solve the issue of chips/particles in the fluid? Were the particles in the fluid a problem to him, or was that an inherent part of the process that nobody in the world had yet eliminated, and a massive-scale undertaking to attack, when he had a simpler countermeasure in place that did eliminate the problem/effect? Would that require a complete process and/or equipment re-design? How long would that take and how much money would that cost? Would the new process/equipment/fixture/product design/etc that eliminates the DEEPEST, TRUE root cause actually 100% guarantee prevention of this problem? Would it create a “butterfly effect” by creating other new problems with a new design that fixed one problem and created another? Ohno’s magic was in employee involvement/empowerment to affect change. Anyone can do 5-Why. Anyone can do PDCA. That is why those quick/easy tools were used for immediate improvement. In some Toyota plants, if they have under 1000 andon pulls per shift, they’ll decrease WIP to force more failures so more problems come to the surface without inventory to hide the problems. Then the problems can be fixed more quickly. I think we all want to find the actual, deepest, final true root cause and fix it. Is that always going to mesh well with a culture of people who constantly solve/fix problems live-time, every day, because they use a simple methodology of 5-why and have the freedom to do PDCA cycles as part of the Toyota Kata and try things to see if they work? I don’t know exactly how, but I know the andon-pull data at Toyota is collected, analyzed, and fed back to the design teams to show what problems poor design in machinery, fixtures, processes, etc caused in the plants, so they can be corrected in the big picture design processes, and I assume then the DEEP, TRUE root cause you folks are talking about is tackled in a long-term, expensive manner. In the meantime, their production folks work in empowered facilities affecting instant change and optimizing performance literally non-stop and live-time. So the Ohno example here is only half of the Toyota story and methodology of how root cause detection is fed back for improvements – but its the simple, quick, and effective half we can all do TODAY, without big dollars or big changes!

  • Ron Zanoni says:

    None of the examples were good. They drilled down to one root cause when we know typical problems have much more. The typical 5-Why method is very superficial.

    • Joe Sommer says:

      And this is why it may be necessary to do multiple 5 Whys around a problem and also why its important to develop themes of multiple causes from the fishbone process. If you think one 5 Why is going to get you to root cause, you have a lot of learning to do!

  • Julia Fletcher says:

    5-why’s are limited to the person’s current knowledge and biases. It doesn’t prompt for further data gathering, investigation, or consideration of other & multiple factors/causes.

  • Mark Paradies says:

    5-Why User: But 5-Whys only takes five minutes.

    Me: What did you learn in those 5 minutes?

    5-Why User: Well, I already knew the answer.

    Me: Ahhh … That’s the problem. Not your knowledge but what you think you know.

    • Tauhid Anasri says:

      I have seen several example of people solving the problem with 5why with already know root cause. they will first fill the root cause and ask question in reveres to fill the document. 5 why does not, may not, or can not solve problem with multiple causes. but it is still a good tool to challenge the thought process and approach of patching the problem than solving the root causes “IF” used correctly

  • Pat says:

    I find most of your 5 why examples to be very poorly written. In many cases you state the negative: “Because we “don’t have”, “we could not” . In other words you are describing what actually did not happened as opposed to a statement of what actually did happen.

    Example: (Bad) “Because the organization does not have an enterprise planning methodology”.
    Example: (Better) “Because the current culture allows excessive variation and undefined detail in it’s planning process.

    • Mark Paradies says:


      Thanks for your comment.

      These aren’t my examples. They are from the internet and elsewhere. The first four examples were published as good examples by people who were promoting 5-Whys as a good practice for root cause analysis. #5 and #6 are jokes.

      I see many real examples like #1-4 and that is the point.

      Yes, you could probably improve these examples but they still would not be good root cause analysis.

      Thanks again,


  • Megan says:

    #2 RCA conveniently diverts blame away from the surgeon to the poor tech who is new in the department, and then ultimately to HR. Typically, in medical examples if the 5 Whys goes down the path of blaming people, I will ask the group to do it again and this time focus on process not on people. Otherwise it’s an endless loop of “short staffed” or “lack of training” for every single problem imaginable.

  • Tim says:

    #1 – I get that no filter is an immediate solution to the problem of the robot ceasing to function. And that a new filter should be fitted asap – once any cleaning of unwanted materials has been conducted. However, I feel there is room for more “Why’s” in order to get to the root cause of the issue – that is, to stop this from happening again. Is it a breakdown in people, processes, KPI’s unintentionally influencing poor behaviours or others? I feel there is still some way to go to get to the root cause of this issue.

  • Mark Paradies says:

    A great bunch of comments! Thanks for reading and replying.


  • Mark Paradies says:

    This article has been posted for quite a while and I still like reading the comments. If you want to comment, it’s not too late!

  • Z1rat says:

    What 5 whys need to be doing is adding value, quite often I see 5 whys completed because that’s the companies process and it has to be done (a chore)
    What it should be is 5 whys and an A. A for F@CKING ACTION!! and an S for Someone do do the F@cking Action! Instead of patting themselves on the back and closing the 5 whys off. Rant over, enjoy your day!

  • Thank you says:

    Thank You

  • Sergio says:

    Personally I think 5Whys is not a good tool to find real RC.

  • yousef atala says:

    thank you

  • Narendrababu says:

    Dear Talent,
    I was searching the founder of the ?…? analysis. I came to know through your website….. thank you so so much….. I will rate all you examples as good, better and best….. because I clearly understood the why why analysis….. it is given by God… the all might….. the best example is the God’s manifestation SRI Gauthama Buddha….. He also asked 5 time why and he got the great power and he answered(right answer) all the question you can feel nd the buddhas 5 why questions in Google if not……

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