The Five Whys is a simple but powerful problem-solving technique used to identify the root cause of an issue. It involves repeatedly asking “Why?”—typically five times—to move beyond surface-level symptoms and uncover the underlying problem. Originally developed by Sakichi Toyoda for Toyota’s manufacturing processes, this method is now widely applied in business, quality control, and evaluation.
How does the Five Whys work? #
The steps involved in the Five Whys are:
- Identify the Problem – Clearly define the issue that needs investigation.
- Ask “Why?” – Determine the immediate cause of the problem.
- Repeat the Question – Ask “Why?” again to explore deeper causes.
- Continue Until the Root Cause Emerges -Usually, five iterations are enough, but more may be needed.
- Develop a Solution -Once the root cause is identified, implement corrective actions to prevent recurrence.
For example, there is a problem that the project missed its deadline.
Applying the Five Whys, we get: #
- Why? The final report was delayed.
- Why? The data analysis took longer than expected.
- Why? The data was incomplete.
- Why? Some team members didn’t submit their reports on time.
- Why? They were unclear on the deadline.
We, thus, establish the Root Cause to be poor communication about deadlines.
What are the benefits of the Five Whys? #
- Quick and Easy to Use – The Five Whys require no complex tools or data analysis. Encourages Critical Thinking – It helps teams focus on causes rather than symptoms.
- Prevents Recurring Issues – It addresses the root cause rather than temporary fixes.
What are the limitations of the Five Whys? #
The method relies on accurate information and may oversimplify complex problems if not applied carefully.
The Five Whys is a valuable tool for uncovering root causes, improving processes, and making informed decisions.
List of recommended resources #
For a broad overview #
This post by Atlassian gives a brief overview of the 5 Whys Analysis, how to conduct it, along with its benefits.
The 5 Whys Explained – Root Cause Analysis
This brief video tutorial by EPM explains how to use the 5 Whys technique to find the root cause of a problem. The video also explains the model’s advantages and disadvantages and how to deploy countermeasures at all levels of an analysis.
For in-depth understanding #
The 5 Whys Explained | Root Cause Analysis | Quality Management Certification | Invensis Learning
This video by Invensis Learning helps understand the 5 Why analysis, how and when to use it, as well as its importance, rules, and criticism of the model. The video provides an in-depth understanding of the 5 Whys technique.
This article by Olivier Serrat gives an in-depth understanding of the Five Whys techniques, providing a step-by-step explanation of the entire process of conducting a 5 Whys analysis.
Case study #
The use of 5-WHYs technique to eliminate OEE’s speed loss in a manufacturing firm
This paper by Samuel Benjamin, M. Srikamaladevi Marathamuthu, and Uthiyakumar Murugaiah studies how the 5-whys analysis technique, which has been primarily known to improve the OEE’s quality loss and changeover loss, has been proven to be an effective approach to also tackle speed loss, a loss which has been regarded as the most dominating loss among all the types of OEE’s losses and a difficult one to eliminate.
This research utilizes the 5 Whys methodology to explore the state of student engagement programs within the Supreme Student Government (SSG), focusing on their effectiveness and levels of student participation.
