Learning Loop Playbooks Learning Loop

Engineering, User experience, Product management

5 Whys

The 5 Whys is a problem-solving technique used to identify the root cause of a problem by asking "why" five times.

Also called: Five Why Analysis, 5 Why Technique, 5 Why Root Cause Analysis, 5 Why Problem Solving, and 5 Why Methodology

See also: Assumptions Collection, Fishbone Diagram, Five Whys, Starbursting, Why-How Laddering

Relevant metrics: Number of Problems Identified, Number of Root Causes Identified, Number of Solutions Implemented, Number of Problems Resolved, and Time to Resolve Problems

In this article

5 Whys: A Problem-Solving Tool for Root Cause Analysis

The 5 Whys is a problem-solving tool used to identify the root cause of a problem. It is a simple yet effective technique that can be used to identify the underlying cause of a problem, allowing for the development of an effective solution. The 5 Whys is a process of asking “why” five times in order to get to the root cause of a problem.

The 5 Whys is a useful tool for problem-solving and root cause analysis. It can be used in a variety of situations, such as when trying to identify the cause of a customer complaint, a production issue, or a quality issue. It can also be used to identify the root cause of a problem in a process or system.

The tool can work very well in identifying the root cause of a problem quickly and efficiently. By asking “why” five times, it allows for a deeper understanding of the problem and its underlying causes. This understanding can then be used to develop an effective solution.

Being useful to quickly identify the root cause of a problem in a variety of situations and in turn develop an effecting solution, it is both simple and effective. Asking “why” five times allows for a deeper understanding of the problem and its underlying causes.

Example of applying the 5 Whys

1. Why did the project fail?
Answer: The project failed due to inadequate planning and lack of resources.

2. Why was there inadequate planning?
Answer: The project team did not have a clear understanding of the scope of the project and did not allocate enough time and resources to complete it.

3. Why did the project team not have a clear understanding of the scope of the project?
Answer: The project team did not receive adequate training and guidance from senior management.

4. Why did the project team not receive adequate training and guidance from senior management?
Answer: Senior management did not provide the necessary support and resources to ensure the project team had the necessary skills and knowledge to complete the project.

5. Why did senior management not provide the necessary support and resources?
Answer: Senior management did not prioritize the project and did not allocate enough resources to ensure its success.

Where did 5 Whys come from?

The term 5 Whys is a problem-solving technique developed by Sakichi Toyoda, the founder of Toyota Motor Corporation. It is a simple yet effective tool used to identify the root cause of a problem. The technique involves asking “why” five times in order to get to the root cause of the problem. The idea is that by asking “why” five times, the problem can be identified and solved more quickly and efficiently. The 5 Whys technique is based on the idea that most problems can be solved by asking “why” five times. This technique is used in many industries, including manufacturing, engineering, and software development. It is also used in the fields of quality management and process improvement.

Applying the 5 Whys Method for Problem-Solving

The premise of the 5 Whys method is that asking “why” five times will lead to the root cause of the problem. Its effectiveness however, depends on the questions you ask. Be thorough, open-minded, consider alle possible causes, and ask questions that are relevant to the problem. Patience can help, as can take time to ask the necessary questions.

  • Step 1 of the 5 Whys is to identify the problem. This can be done by asking questions such as “What is the problem?” or “What is the issue?”
  • Step 2 is to ask “Why?” and answer the question. This is done by asking “Why is this happening?” or “What is causing this problem?”
  • Step 3 is to repeat the process until the root cause is identified. This is done by continuing to ask “Why?” until the underlying cause of the problem is identified.

Benefits of Implementing the 5 Whys

  • Increased Efficiency. The 5 Whys technique helps to quickly identify the root cause of a problem, allowing teams to focus their efforts on the most effective solutions. This can help to reduce the amount of time and resources spent on solving the issue.
  • Improved Problem-Solving. By asking “why” five times, teams can gain a better understanding of the underlying cause of a problem. This can help to ensure that the right solutions are implemented, leading to better outcomes.
  • Improved Communication. The 5 Whys technique encourages teams to communicate more effectively. By asking “why” five times, teams can gain a better understanding of the issue and come to a consensus on the best solution.
  • Improved Teamwork. The 5 Whys technique encourages teams to work together to identify the root cause of a problem. This can help to foster collaboration and improve team morale.
  • Improved Quality. By identifying the root cause of a problem, teams can ensure that the right solutions are implemented. This can help to improve the quality of products and services, leading to better customer satisfaction.

Challenges of Implementing the 5 Whys

  • Time. The process can be time-consuming, as it requires a deep dive into the root cause of a problem. This can be difficult to do in a short amount of time, especially if the problem is complex.
  • Resources. The right people, data, and tools available might be necessary for the method to be successful. Without the right resources, it can be difficult to discover the rights questions to ask.
  • Communication. The 5 Whys process requires effective communication between team members to be successful - it is a collaborate method where participants build on each others input.
  • Focus. The 5 Whys process requires focus and discipline to be successful. Without focus, it can be difficult to get to the root cause of a problem.

The 5 Whys technique is not a substitute for other problem-solving techniques, such as brainstorming or root cause analysis. It should be used in conjunction with other problem-solving techniques to ensure that the root cause of a problem is identified and addressed.

Examples

Toyota

In the early 2000s, Toyota used the 5 Whys technique to identify the root cause of a problem with the accelerator pedal in some of its vehicles. By asking “why” five times, Toyota was able to identify that the problem was caused by a design flaw in the accelerator pedal.

Microsoft

Microsoft used the 5 Whys technique to identify the root cause of a problem with its Windows operating system. By asking “why” five times, Microsoft was able to identify that the problem was caused by a bug in the software code.

Amazon

Amazon used the 5 Whys technique to identify the root cause of a problem with its online shopping website. By asking “why” five times, Amazon was able to identify that the problem was caused by a design flaw in the website’s user interface.

Apple

Apple used the 5 Whys technique to identify the root cause of a problem with its iPhone. By asking “why” five times, Apple was able to identify that the problem was caused by a hardware issue with the phone’s battery.

Relevant questions to ask
  • What is the problem that needs to be solved?
  • What is the root cause of the problem?
    Hint The root cause of the problem is the underlying cause of the issue.
  • What are the potential causes of the problem?
    Hint The potential causes of the problem could be related to the environment, technology, processes, people, or other factors.
  • What data or evidence do I have to support my hypothesis?
    Hint The data or evidence needed to support the hypothesis could include surveys, interviews, observations, or other forms of data collection.
  • What are the potential solutions to the problem?
    Hint The potential solutions to the problem could include changes to the environment, technology, processes, people, or other factors.

You might also be interested in reading up on:

People who talk about the topic of 5 Whys on Twitter
Relevant books on the topic of 5 Whys
  • 14 Management Principles from the World's Greatest Manufacturer by Taiichi Ohno, The Toyota Way (2003)
  • Value Stream Mapping to Create Value and Eliminate MUDA by John Shook, Learning to See (1999)
  • The Story of Lean Production by Daniel T. Jones, The Machine That Changed the World (1990)
  • Lean Production Simplified by James P. Womack, Daniel T. Jones, and Daniel Roos, The Machine That Changed the World (2005)
  • How to Implement the Toyota Production System in Your Organization by Jeffrey K. Liker, The Toyota Way (2004)

Want to learn more?

Receive a hand picked list of the best reads on building products that matter every week. Curated by Anders Toxboe. Published every Tuesday.

No spam! Unsubscribe with a single click at any time.

Community events
Product Loop

Product Loop provides an opportunity for Product professionals and their peers to exchange ideas and experiences about Product Design, Development and Management, Business Modelling, Metrics, User Experience and all the other things that get us excited.

Join our community

Made with in Copenhagen, Denmark

Want to learn more about about good product development, then browse our product playbooks.