What are the 5 Whys?

Although asking “Why?” might be the favorite strategy of your three-year-old child, it can also teach you valuable Lean Six Sigma lessons. The Analyze phase of the Lean Six Sigma DMAIC (Define Measure, Analyze and Improve, Control) methodology uses the 5 Whys diagram. This is a powerful Lean Six Sigma tool, which does not require data segmentation, hypothesis testing, or regression, and can often be done without the need for a data collection plan.

Asking the question “Why?” five times a day is a good way to uncover the cause of the problem. You will often find the root cause of a problem by asking another question. This diagram technique is known as “5 Whys” in six sigma, but you might find that you need to ask the question less than five times before you can find the problem.

Why the 5 Whys?

The Five Whys in six sigma is a powerful non-statistical assessment method. It can trace problems to their root cause that weren’t obvious or clear. The 5 Whys is a simple and effective tool

The Benefits

  • Understanding how one process can lead to a series of problems
  • It helps to identify the root cause of a problem
  • Highly effective without complex evaluation techniques
  • Find out the relationship between root causes

When should you use this method?

  • Problems that involve interactions or human factors. Human error may be involved in any aspect of the process.
  • Simple to moderately complex problems
  • This method may be combined with other methods to solve more complex problems

Important Things to Remember

  • You can work backward to ensure that you have the correct answer for each ” Why”. (Answer the ” What?” + “and consequently” + the Problem Identified for That Question
  • Differentiate causes from symptoms.
  • Always base your answers on facts and data
  • It is possible to break down your answers however many times you wish. The more you can answer, the better.
  • Last, but not least, evaluate the process and not the people.

Origin of 5 Whys Diagram

The Toyota Production System includes the 5 Whys method. The technique was developed by SakichiToyoda, an industrialist and Japanese inventor. It became part of the Lean philosophy.

“Toyota’s scientific approach to solving problems is to ask why five-time whenever we find one… If you repeat why five times, it becomes obvious the problem and its solution.” Taiichi Ohno

A well-informed decision is key to the success of this technique. This means that decision-making should be informed by an understanding of the actual situation on the floor.

This means that people with real-world experience should be involved in the root cause analysis process. They can provide you with the best information about any problem in their field of expertise.

How to get started

The 5 Whys method may be able to help you achieve continuous improvements at all levels of your company. These are the basic steps to follow.

Forge a team

You should try to get people from different departments together. Each member must be well-versed in the investigation process.

You will gain unique perspectives by joining a cross-functional group.

This will allow you to gather enough information to make an informed choice. This is not an isolated task and must be done by the entire team.

Define the problem

Talk about the problem with your team and create a problem statement. This will allow you to define the issue that you are investigating.

This is crucial because it can be time-consuming to investigate a broad problem with unclear boundaries. To find an effective solution, you need to be as specific as possible.

Ask Why

One person can be empowered to lead the entire process. The team leader will be asking questions and trying to keep the team on track. Your answers should be based on facts and actual data, not on your emotions.

Facilitators should continue asking “Why” until the team is able to identify the root cause of the problem.

Do not ask too many Whys. You may get a lot of unfounded suggestions and complaints if you continue to ask. Concentrate on the root cause. Sometimes, there may be more than one cause. The six sigma 5 Whys analysis can look more like a matrix, with branches. This could help you identify and fix organizational problems that can have a permanent negative impact on overall performance.

What is the 5 whys diagram in six sigma?
What is the 5 whys diagram in six sigma?

Get involved

Once the team has identified the root cause, it is time for corrective action. To prevent recurring problems, all members of the team should participate in a discussion.

Once the decision has been made, the responsible person in charge of executing the correct actions and overseeing the entire process should be a member of the team.

After a period, the group should meet again to verify that their actions had any positive effects. If not, it is worth re-doing the whole process.

The case should be documented at the end and sent to all levels of the organization. This information can give a clear overview of the different problems that a team might face and how they can be solved.

5 Whys, and the Fishbone Diagram

You can use the 5 Whys individually or as part of the fishbone. The fishbone diagram allows you to explore all possible or actual causes that could lead to a defect or failure. Once you have established all the inputs on the fishbone, the 5 Whys technique can be used to drill down to the root cause.

In Summary

The Five Whys (5 Whys) in six sigma is a method that is an effective and simple tool to solve problems. Its main purpose is to identify the cause of a problem by asking a series of “Why” questions.

  • Your team can use the 5 Whys method to help them focus on the root cause of any problem.
  • This encourages team members to work together for continuous improvement and not to blame others.
  • This gives your team the assurance that they can solve any problem and avoid recurring failures.
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