Interrelationship Diagram

An interrelationship diagram (ID) shows how different issues are related to one another. It helps identify which issues are causing problems and which are an outcome of other actions. It also shows the strength of each influence.

An interrelationship diagram consists of a set of boxes, one representing each issue to be considered. It is organized in a radial pattern on the page. Connecting lines between the boxes indicates their relationship. Arrows show direct relationships and distinguish causes from effects.

Interrelationship diagrams can be extremely useful when trying to sort out possible causes 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.

Interrelationship diagram example

How to Create and Use an Interrelationship Diagram

  • Identify the problem. Decide what problem to solve 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, identify 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 number of outgoing arrows is a key cause of the problem. Any item with many arrows pointing to it is a main outcome.
  • Solve the issue. Discuss a way to solve the issue by focusing on the main cause.