Lean insight: 'Five Whys' problem-solving

The Lean Learning Center
Tags: lean manufacturing

Applying the right lean tool for a given problem follows directly from mastery of the lean principles. This article provides an explanation of the “Five Whys” problem-solving tool.

Proper uses of the tool:
1) As a structured approach to solve problems as they occur
2) As a framework for a team to work through a more complex problem

Improper uses of the tool:
1) To emphasize the person or blame, turning the Five Whys into the Five Whos.
2) To emphasize documentation at the expense of applying the tool. When problem-solving becomes a tedious, desk-intensive process, it is a punishment that gets used as little as possible.

Description of Five Whys tool, how-to

Some examples of good problem statements include:

  • Overall customer complaints are up 50 percent
  • The No. 3 press is consuming $2,000 in repairs monthly


Why did the circuit board burn out? Because it overheated.
Why did it overheat? Because it wasn’t getting enough air.




A vital final step of the process is verifying that the solution worked. This should be done by first seeing that the countermeasure is sustainable and then making sure that the original condition – the symptom – has been eliminated. There are two purposes. The first is to ensure we met our objective: eliminating the adverse condition. The second is where learning occurs. By verifying each countermeasure, we learn what works and what doesn’t, improving our knowledge both of the process we are trying to manage and improve in addition to problem solving process itself.

Variations on the tool
The Five Whys can be built into many other problem solving processes. Many companies create proprietary problem solving processes that are based on having a common way to communicate or save for learning and history. The Five Whys can be utilized as a formal part of a larger process or by the user to determine the root cause, which then gets input into the formal process. Also, tools, such as Six Sigma, can help find the answer to each successive ‘why’ being asked, but does not replace the process of digging down layer by layer.

How tool relates to rules and principles

Key behaviors that must accompany the Five Whys include: 1) surfacing problems quickly; 2) using them as opportunities to move closer to the ideal state; and 3) focus on the process, not on blaming the person. The principle of Create a Learning Organization is also greatly enabled through the practice of the Five Whys. The Five Whys can become the primary driver of daily learning about the management and improvement of the process.


About the author:
The Lean Learning Center was established in 2001 to help companies overcome the barriers to successful lean transformation. In conjunction with its corporate partner Achievement Dynamics, a provider of management consulting, the center provides a full complement of lean transformation services. Partners Jamie Flinchbaugh and Andy Carlino have recently authored a book titled The Hitchhiker’s Guide to Lean, published by the SME. For more information visit www.hitchhikersguidetolean.com.

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