We’re all familiar with the 5 Whys as a path for root cause analysis. But is it enough? What’s beyond the 5 Whys? Are there times they shouldn’t be used? Are there other alternatives?
We’ll explore those questions and provide answers from experts.
First, Paul Allen, Lean Six Sigma consultant of Allen and Partners Limited, discusses why this methodology doesn’t work.
5 Whys seeks to determine a single root cause. However, there are usually a multiple of causes for a problem. Only when your processes are in control and a special cause occurs can the 5 Whys can be used to determine the single root cause.
Paul says that is rarely the case. When processes are not in control, the system is in a state of chaos. In those multi-causal situations, it’s better to focus on input variables using a cause and effect diagram. It would not work.
You can view Paul’s presentation here.
Next, Shon Isenhour, founding partner of Eruditio LLC, an educational firm, offers another perspective with 5 reasons that 5 Whys is not a good root cause analysis tool.
- There may be more than one cause. 5 Whys as it is most often used only addresses one branch of the causal chain, either the condition or the action.
- Analyzing only one cause may prevent optimal solutions
- Results are not repeatable. Different results depend on who is asking the questions.
- Answers are based on current knowledge and experience.
- Using this method causes a tendency for investigators to stop at symptoms rather than going on to lower-level root causes, which leads to the problem recurring.
You can access Shon’s brief article here.
HatRabbits, a Dutch agency for business creation and innovation, discusses the 5 Whys. Near the end of their article, they mention that the 5 Whys are not always applicable.
“… sometimes a problem is too complex to analyze with 5 simple questions.”
When is that the case?
“You’ll recognize problems that are unfit for the 5 Whys method when you can’t easily answer the first ‘why’ question with a single answer. Some problems have many potential causes and simply need a more elaborate analysis.”
You can access this HatRabbits article here.
Nonetheless, this methodology is widely used.
In the next HatRabbits article, they cover the four things to remember when using this method in order to prevent issues.
- Begin with a problem statement
- Make sure you know enough details to confidently answer the questions
- Ask “Does this question bring me closer to the core of my problem?”
- Ask “Does this answer bring me closer to the core of my problem?”
You’ll find this HatRabbits article here.