Interrelationship Diagrams
Interrelationship diagrams are specialized cause-and-effect diagrams that aim to visually represent the complex interactions among various variables involved in a problem. These diagrams fall under the Evaluation knowledge area, and are particularly useful in situations where the relationship among multiple variables is intricate, and where causes and effects are not linear or straightforward.
Objective
The primary objective of an interrelationship diagram is to identify and analyze the complex, interrelated causes and effects that contribute to a particular problem. By isolating each dimension of a problem, it enables stakeholders to understand the relationships between causes and effects. It further aids in identifying which causes are primary in generating a problem.
Methodology
Identify Causes and Effects: List all the potential causes and effects related to the problem at hand. It's practical to limit this list to a maximum of ten to maintain focus.
Draw Interrelationships: Use arrows to represent the cause-and-effect relationships between the factors. The arrow should point from the cause to the effect. If two factors influence each other, recognize the stronger influence and note it.
Analyze Arrows: Look at the number of incoming and outgoing arrows for each factor.
- Factors with a large number of incoming arrows are key outcomes (effects) and can serve as useful measures of success or as variables to be monitored closely.
- Factors with a large number of outgoing arrows are key sources of the problem (causes). These should be prioritized for needs assessments.
Emphasize Significant Factors: The factors that are significant in terms of their role as a cause or an effect can be emphasized, often by making them bold, for easier identification and focus.
When to Use
This diagram is most effective when dealing with complex problems having multiple variables, especially when those variables have non-linear, interrelated cause-and-effect relationships.
Limitations
- Like the fishbone diagram, it is not exhaustive in identifying all root causes.
- It is dependent on the expertise of the team constructing it; errors or omissions can significantly affect its usefulness.
Considerations
The value of an interrelationship diagram is primarily realized after it has been fully constructed and analyzed. As participants focus on each dimension individually, the complete picture becomes clear only when the entire diagram is assembled.
By effectively employing an interrelationship diagram, business analysts and stakeholders can gain a comprehensive understanding of a complex problem, which is crucial for the Requirements Life Cycle Management and the overall success of any project.