“The measure of success is not whether you have a tough problem to deal with, but whether it is the same problem you had last year.”— John Foster Dulles Former Secretary of State
5 Whys is an iterative interrogative technique used to explore the cause-and-effect relationships underlying a particular problem. The primary goal of the technique is to determine the root cause of a defect or problem by repeating the question “Why?” Each answer forms the basis of the next question. The “5” in the name derives from an anecdotal observation on the number of iterations needed to resolve the problem.
Not all problems have a single root cause. If one wishes to uncover multiple root causes, the method must be repeated asking a different sequence of questions each time.
The method provides no hard and fast rules about what lines of questions to explore, or how long to continue the search for additional root causes. Thus, even when the method is closely followed, the outcome still depends upon the knowledge and persistence of the people involved. Due to this nature the 5 Whys methodology is a very power tool for the root cause analysis because it forces people to really think about what went wrong.
The vehicle will not start. (the problem)
- Why? – The battery is dead. (First why)
- Why? – The alternator is not functioning. (Second why)
- Why? – The alternator belt has broken. (Third why)
- Why? – The alternator belt was well beyond its useful service life and not replaced. (Fourth why)
- Why? – The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause)
The questioning for this example could be taken further to a sixth, seventh, or higher level, but five iterations of asking why is generally sufficient to get to a root cause.[The key is to encourage the trouble-shooter to avoid assumptions and logic traps and instead trace the chain of causality in direct increments from the effect through any layers of abstraction to a root cause that still has some connection to the original problem. Note that, in this example, the fifth why suggests a broken process or an alterable behaviour, which is indicative of reaching the root-cause level.
The last answer points to a process. This is one of the most important aspects in the 5 Why approach – the real root cause should point toward a process that is not working well or does not exist. Untrained facilitators will often observe that answers seem to point towards classical answers such as not enough time, not enough investments, or not enough manpower. These answers may be true, but they are out of our control. Therefore, instead of asking the question why?, ask why did the process fail?
A key phrase to keep in mind in any 5 Why exercise is “people do not fail, processes do”.
When it comes to 5 Whys there are not so many boundaries. The strong characteristic about 5 Whys is that it allows you to find a root cause within the issue. This broad and inter process root cause analysis can very effective because of characteristic.
However, with the 5 Whys it is very easy to reach a level where it is easy to just blame a person or department. It is important to leave the personal aspects out of the equation and focus on the processes and organisation. Blaming somebody doesn’t help, always try to look at the organisation. So when a particular person is making the same mistake multiple times maybe we should give him or her training to improve his way of working. Or maybe the recruitment process is not how it should be. Just try to prevent blaming people “The concept behind 5 why’s is that you keep on asking the question why did it happen until you reached to the underlying cause.”
- Spears, Stephen. The High Velocity Edge.
- Ivan Fantin (2014). Applied Problem Solving. Method, Applications, Root Causes, Countermeasures, Poka-Yoke and A3. How to make things happen to solve problems. Milan, Italy: Createspace, an Amazon company. ISBN 978-1499122282
This article uses material from the Wikipedia article “Metasyntactic_variable”, which is released under the Creative Commons Attribution-Share-Alike License 3.0.