May 15, 2019 | Mark Paradies

5-Why Examples: The Best and The Worst!

5-Why Examples

I’ve been asked by many … “What do you think of 5-Whys?”

Instead of giving my opinion of 5-Whys, let me get your opinions on which of these six examples are the best (or at least good).

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?

Most of these examples were posted online as best practice examples.

At least one of these examples is obviously bad (but the people who posted it thought it was good).

At least one is a joke. (Let’s call that one 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

#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 web site medical 5-Why example – A patient had the wrong leg amputated:

  1.  Why was the wrong leg was 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 making tool and they 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 web site 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 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!

But what do you think of these examples?

Leave your comments below…


(PS: I’ve had several people e-mail me to ask how this 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

9 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.

  • 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.

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