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ASQ — Problem Solving Tools Resources: Five Whys And Five Hows (4)

By Jean-Pierre Amiel posted 02/23/23 04:44 PM



This fourth article introduces the Five Whys and Five Hows approach. It constitutes a questioning process designed to drill down into the details of a problem or a solution and peel away the layers of symptoms. The technique was originally developed by Sakichi Toyoda who stated that "by repeating why five times, the nature of the problem as well as its solution becomes clear."
Typically, the five whys are used for drilling down into a problem and the five hows are used to develop the details of a solution to a problem. Both are designed to bring clarity and refinement to a problem statement or a potential solution and get to the root cause or root solution.

This series of articles presents techniques to identify a "problem", identify its most likely cause (root cause) and then resolve the situation. These articles are also extracted from ASQ's Quality Resources library which showcases information related to the quality world's Body of knowledge (BOK) and compiled from more than 75 years’ worth of content for all experience levels. It is only meant to be a starting point.

When to Use:

To expand the horizon of a team searching for answers, there are distinct uses for five whys and five hows. Both techniques force a team to develop a better and more detailed understanding of a problem or solution and will be helpful in the root cause analysis process.

  • Use the five hows technique to develop more details of a solution to a problem under consideration — brainstorming and a solution-focused cause-and-effect diagram.

How to Use the approach:
Materials needed: Chart paper and pen/markers.

  1. Draw a box at the top of a piece of flip chart paper and clearly write down the problem or solution to be explored.
  2. Below the statement box draw five lines in descending order.
  3. Ask "why" or "how" five times and write the answers on the lines drawn from number one to five.
  4. It may take less or more than five times to reach the root cause or solution.

Article adapted from: The Public Health Quality Improvement Handbook, ASQ Quality Press.

§ This News post was adapted by J.P. Amiel, ASQ Senior, CQA ret., Web committee Chair, from content at ASQ's Quality Resources pages, which is excerpted and adapted from various publications in the ASQ Quality Press. 

ASQ References:
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