Quality in Healthcare

Five Whys and Five Hows

By Ron Bialek, Grace L. Duffy, and John W. Moran

• The five whys and five hows constitute 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. He states “that by repeating why five times, the nature of the problem as well as its solution becomes clear.”


• 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.


• Edward Hodnet, a British poet, observed, “If you don’t ask the right questions, you don’t get the right answers. A question asked in the right way often points to its own answer. Asking questions is the ABC of diagnosis. Only the inquiring mind solves problems.”

• When we want to push a team investigating a problem to delve into more details of the root causes, the five whys can be used with brainstorming or the cause-and-effect diagram.


• The five hows can be used with brainstorming and the solution-and-effect diagram to develop more details of a solution to a problem under consideration.


• Both methods are techniques to expand the horizon of a team searching for answers. These two techniques force a team to develop a better and more detailed understanding of a problem or solution.

• Draw a box at the top of a piece of flip chart paper and clearly write down the problem or solution to be explored.


• Below the statement box draw five lines in descending order.


• Ask the “Why” or “How” question five times and write the answers on the lines drawn from number one to five.


• It may take less or more than five times to reach the root cause or solution.

Examples of five whys and five hows are below.

Five whys of less vigorous exercise:

Too much TV and video games

Few community-sponsored recreation programs

No family recreational activities

No safe play area

Lack of resources

Five hows of more vigorous exercise:

Less TV and video games

More community-sponsored recreation programs

More family recreational activities

Safe play areas

Excerpted from Ron Bialek, Grace L. Duffy, and John W. Moran, The Public Health Quality Improvement Handbook (Milwaukee, WI: ASQ Quality Press, 2009), pages 168–170.

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