An Ishikawa Diagram shows how different issues are related to one another based on cause and effect. It helps identify which issues are causing problems and which are an outcome of other action. It also shows the strength of each influence.
Ishikawa Diagrams consist of a set of boxes, one representing each issue to be considered, organized radially on the page. Lines are drawn between the boxes to indicate their Ishikawa.
Ishikawa diagrams can be extremely useful when trying to sort out the cause and outcome of a specific problem. Although they do not identify detailed reasons for the problem, they do allow one to analyze broader issues as causes and effects of one another.
- Determine a problem. Decide what problem is to be solved by analyzing its various factors. Place it in a box at the top of the paper.
- Identify issues. Brainstorm to produce any key issues, ideas, reasons, causes, etc., for the problem. Place each in a rectangle on the page.
- Connect the issues. Choose any item to start with and compare it to any other. Decide if the two are related to each other in any way. If they are, decide which is a cause and which is an effect. Use an arrow pointing from cause to effect to show the relationship.
- Identify intensity. If one item has a particularly strong influence on another make the arrow darker; if it is a weak relationship, use a dotted line.
- Analyze. Any item with a large amount of outgoing arrows is a key cause of the problem. Any item with many arrows pointing to it is a main outcome.
- Verify accuracy. Consult with others in the company to add any other issues that may play an important role in the problem and then discuss a way to solve it by focusing on the main cause.