An interrelationship diagram is a tool to identify the root cause of any problem. It is a very useful tool for individuals and businesses. Using this technique, you can easily understand how multiple issues are related to the problem and influence each other. An Interrelationship Diagram presents the issues in boxes, and arrows connect all boxes. Arrows are considered a cause-and-effect relationship between problems. The cause with the highest number of outgoing arrows will be known as the root cause. The Interrelationship Diagram for ABC Company showcases different problems and causes associated with it.