To uncover the root causes of a problem, the 5 why method can be applied. This technique is often used within Lean and is based on asking the five ‘why’ questions, also known as the 5 whys. In this article, you will learn why the questions are asked, how to apply them in your organization, and what benefits the 5 why method delivers.
What is the 5 why method?
The 5 why method has developed within Lean Manufacturing as a widely used technique across various industries. As the name suggests, you ask the same question five times: ‘why?’. By asking ‘why?’ five times, you dig deeper into the issue and reach the true root cause. In practice, five iterations of the question usually deliver the best results, which is why the method is built around this specific number. The 5 why method can be applied in many situations, such as identifying the cause of a problem, waste, or bottleneck in the production process. While it is mainly used during the analysis phase, it also works well in combination with an Ishikawa diagram or as part of the DMAIC model.
What are the benefits of the 5 why method?
Working with the 5 why method provides organizations with several advantages. By repeatedly asking the 5 why questions, you not only gain more insight into the cause-and-effect relationships within internal processes, but you also address problems at their root. This enables the creation of sustainable solutions that eliminate the secondary consequences of the issue (such as time loss or production delays) in the future. Another benefit of the 5 why method is its speed and simplicity. No complex tools are required to apply it, yet it can still be effectively used by the entire team. Together, you focus on the underlying cause of a problem instead of merely treating the symptoms.
How to apply the 5 why method in your factory
Whenever a deviation or problem occurs in a production process, the 5 why method can be applied. It is essential to gather all people involved in the specific process or issue and analyze the situation together. This is done by asking ‘why?’ five times in succession, tracing the problem back to its root cause. By doing so, you avoid makeshift or temporary solutions that do not resolve the issue in the long run. For example, ask why a problem occurred, why it was not addressed immediately, or why it seems to reoccur. The results of the 5 whys are then documented in a report and used to define targeted measures that will prevent recurrence of the incident. If a new or different problem arises later, the 5 why method is simply applied again.
Example of the 5 why method
To give a clearer picture of how the 5 why method can be applied in a production environment, we have worked out an example below.
Scenario: During production, a machine suddenly stops working. This is of course a major issue and should not happen unexpectedly. To analyse and sustainably solve the problem, you apply the 5 whys. It looks like this:
Problem: The machine stops unexpectedly during production
The 5 whys:
- Why did the machine stop? → The motor overheated.
- Why did the motor overheat? → The cooling fan failed.
- Why did the cooling fan fail? → The fan fuse blew.
- Why did the fuse blow? → There was a short circuit in the wiring.
- Why was there a short circuit in the wiring? → The wiring was worn out and not replaced in time.
Conclusion: The root cause of the problem was worn wiring due to overdue maintenance. The solution lies in adjusting the maintenance schedule to check and replace wiring more frequently on a preventive basis. If the 5 why method is applied correctly, you can also view the situation in reverse: the worn wiring caused the short circuit, which in turn caused the fuse to blow in the cooling fan, which then caused the motor to overheat, and so on.
How can the EZ-GO app support the use of the 5 why method?
The EZ-GO app provides a structured digital environment in which the results of a 5 why analysis can be recorded and secured. For example, if a countermeasure from the analysis is to use different types of caps to prevent the wrong cap from being placed on the wrong pipe, this action can easily be incorporated into a work instruction, or embedded in training and assessments within EZ-GO. In addition, tasks can be created to perform extra inspections. In this way, the app helps teams implement and sustain improvements directly on the shop floor, while ensuring that all follow-up is clearly managed within the same platform.
Questions about the 5 why method or the EZ-GO app? Get in touch!
Is your organization ready for effective solutions that can be applied anytime, by anyone? Then a demo of the EZ-GO app is highly recommended. Whether you have questions about the 5 why method or about the EZ-GO app itself – we are here to help. Feel free to contact us for more information!