Root Cause Analysis:
Get to the Root of the Problem

Use the 5- Whys Tool

The 5-Whys is a root cause analysis tool that was pioneered by the Toyota Corporation. It was used on the shop floor by quality improvement teams to diagnose and fix process problems.

The technique involves a facilitator asking the team a question. "Why does a particular process problem occur?" The team responds by providing answers to the question posed by the facilitator.

This root cause analysis tool can be applied in either a structured or unstructured manner.

The Five Whys: Structured Technique

The facilitator poses the question, "Why is the Jefferson Memorial crumbling?"

Each team member is offered the opportunity to provide an answer to this question. The rules of brainstorming apply to this portion of the exercise. Ideas are accepted without evaluation or criticism.

The facilitator or team members record each answer on a flipchart or on a sticky note.

The team then decides which brainstormed response to pursue for the second "Why?" question.

The facilitator writes this response at the top of the second flipchart page.

Alternatively, the facilitator can move the Post-it note that contains the selected idea to the second flipchart. That Post-it note and serves as the header for the flipchart containing the second "Why?" question.

The facilitator then asks the team the second "Why?" question. And again records each team member's response on the second flip chart page.

This process continues until 5-Whys have been asked and answered and the team has discovered the root cause of the problem.

The Five Whys: Unstructured Technique

The unstructured method is very similar to the structured method. A team applying the unstructured method, might not have a facilitator leading the exercise.

The team leader might establish the first question and solicit the "Why?" responses from team members. Anyone can call out his idea without the formal polling of each individual.

Someone records each idea on a flipchart or Post-it note. The team decides which idea has the most merit and uses this idea for the next round of questioning.

This process continues until the five "Whys?" have been asked and the team has identified a root cause of the process problem.

I do not recommend using the unstructured approach with a team that has not had previous experience in using this tool.

Team members tend to under estimate the complexity of the technique. When using this form of analysis, the team often has to go back and select a different thread of the problem to pursue.

It is not at all unusual to encounter dead end threads that do not lead to a root cause.

When this happens, the team needs to go back and pursue a different thread. The team might need to repeat this step of the analysis until they find a productive thread that leads to a viable root cause.


I first saw this process analysis technique demonstrated in a Juran Institute "Quality Minute" video.

This video does a wonderful job of illustrating the 5-Whys technique. However, it might leave you with the impression that this analysis is easy and straightforward.

I have found that teams usually struggle with this analysis. However, their struggles are usually rewarded with unexpected and very helpful root causes.

You might encounter a team of left-brained analytical thinkers, who strongly object to this technique. If you encounter this situation, you might want to have this team create a fishbone diagram or cause and effect analysis, instead of this one.

Tips :

• Use the structured method for inexperienced teams.

• I like to use five flip chart pages and Post-it notes to record ideas.

• Record one idea on each Post-it note.

• The sticky notes can then be moved from page to page to flow with the analysis.

• This also preserves the initial offering of ideas which makes it easier to go back and follow an alternative thread through the analysis.

• If you are working on a reengineering or large process redesign project, you may be able to divide into functional-area based sub- teams to perform the root cause analysis.

If the process problem is wholly contained in one functional area, this approach might make sense and expedite the problem identification process.

. If your team is stuck in its left-brain, try a fishbone analysis.

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