A fishbone diagram is a visual layout of the possible causes of a problem. It is structured to show a number of branches, and so looks somewhat like a fish skeleton (hence its name). A fishbone diagram begins with a single line, at the end of which is stated the problem to be solved. Then a number of branches are added that denote the general areas in which the causes of problems may be found. The generic headings most commonly used for these problem areas are:
- Methods (procedures)
- Machines (equipment)
With this basic structure in place, a facilitator then collects possible causes from the team assigned to the problem, and writes them into the diagram. The outcome is a diagram similar to the following sample. This approach does a good job of organizing information about the causes of a problem.