The Ishikawa diagram portrays the causes of an effect and is used in manufacturing and other services such as product development.
The purpose is to let management determine which problems or causes have to be tackled to promote or avoid a specific event.
Other purposes include using it as a methodology for developing product designs that fix practical problems.
It’s also used in quality defect prevention to bring to light factors that cause a negative effect.
Decide on a problem or negative effect.
Put down the problem in the center of the drawing tool, box it then draw an arrow going to it.
Think of the main categories of causes for the problem or negative effect.
Put down the causes as branches from the main arrow.
Brainstorm possible causes and ask ‘Why does this happen?’. Each answer should be a branch from the appropriate category
Ask the question ‘Why does this happen?’ again. Put down sub-causes branching from the causes.
When you’re all out of ideas, look to parts of the chart where ideas are weak.