The 5 Whys


For want of a nail a shoe was lost,

for want of a shoe a horse was lost,
for want of a horse a rider was lost,
for want of a rider an army was lost,
for want of an army a battle was lost,
for want of a battle the war was lost,
for want of the war the kingdom was lost,
and all for the want of a little horseshoe nail.

Confesio Amantis

Have you heard of the 5 Whys?

The 5-Whys is an Analysis Method used by Toyota Motor Corporation to find the root cause of a problem, not the symptom. It digs beneath the outward symptoms to find the cause. The premise is that systems fail, not people. It is a very powerful management tool and is closely related to the Cause and Effect Fishbone diagrams

http://www.mindtools.com/pages/article/newTMC_03.htm

The method involves asking “Why …?” five times in succession.

This may sound simplistic; however it requires thought and intelligent application in order to ask the right Why?

As the questioner, you may need discipline and persistence to follow the methodology. The answer to one question leads you into framing the next Why…?

It may not be possible to ask or answer the next question immediately as you may need to collect and analyse additional information to ensure the question is answered properly. This may also require brainstorming.

This methodology requires practice and the more you use and apply it, the more you’ll begin to find the real underlying (root) causes of problems. By the time you get to the fourth or fifth Why…? you are very likely to be looking at management practices rather than just symptoms.

Here is a simple example.

Problem: The car won’t start.

1. Why? The battery is flat. (Symptom)

2. Why is the battery flat? The alternator is not working. (Symptom)

3. Why is the alternator not working? The alternator belt is broken. (Symptom)

4. Why is the alternator belt broken? The alternator belt was well past its useful life and had not been replaced. (Symptom)

5. Why is that?

Root Cause: The vehicle was not maintained in accordance with a maintenance schedule. There is no effective maintenance system in place.

Remember the Space Shuttle Challenger tragedy in 1986, http://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disaster
when the space craft exploded shortly after launch and was watched live on TV by millions?

This was caused by faulty ‘o’ rings and was a systemic failure of management systems in the space program.

Using the 5 Whys.
When solving a problem using the 5 Whys, a common error is to stop too soon. People keep taking the first or second simple answer, blinded by the symptoms or settling for the first ‘apparent’ cause. Don’t accept ‘it’s just human error’ or ‘they made a mistake’. Mistakes happen this is why robust quality systems are needed. Systems must be designed with built in controls that help prevent the problem occurring in the first place, detect it if it does occur and then do something effective to stop it recurring.

Remember, you are looking for the root cause and simple answers are most likely to be symptoms (i.e. the outward signs of a problem that has been observed) and are unlikely to be the real root cause. Good quality management systems insist on a systematic approach to dealing with nonconformity involving corrective and preventive actions. This can lead to massive improvements in an organisation’s performance.

The example of the flat battery illustrates how a system of maintenance would have prevented the problem occurring. Money would have been saved on repairs, time would not have been lost whilst having the vehicle repaired and staff and customers would not have been delayed whilst waiting for the vehicle and so on.

Can you think of a problem in your business or workplace where you could uncover the root cause using the 5 Whys?

3 thoughts on “The 5 Whys

  1. I love this technique which I use to investigate issues AND to assess market opportunities. Asking the 5 WHY questions and also the 5 HOW questions is a great way to understand who your ideal customers are, their wants and real needs.

    • Yes, it certainly works if you concentrate and ask the right questions (and of course listen to the answers). too often we deal with symptoms rather than the root causes of problems

  2. Pingback: The lessons from railway tracks | 5-Dimensionz

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