Three Types of System Diagrams
Rich pictures are unstructured pictures and usually drawn by hand. They depict all the major aspects of a problem of interest.
The aim of a rich picture diagram is to capture the full extent of the issues without giving any thought to their groupings or relationships, however, some related aspects of relationships between different issues are frequently illustrated through relative positions or simple lines connecting those issues.
Multiple cause diagrams are used to explore why changes or events happen.
The purpose of the diagrams is to examine the multiple causes behind particular events and processes. Here one looks primarily at the causal chain behind processes. Developing a multiple cause diagram may identify important feedback loops that can provide insights into the multiple causes of a system’s behaviour and how to make undesirable behaviour less likely.
Influence diagrams are a type of systems map that show the relationships between the components within the system. They highlight the relationships and influences between the system’s components.
An extension of influence diagrams are sign graph diagrams (not shown). Analysing the relationships between the components can tell if the component at the beginning of an error will cause a change in the same (indicated by a “+”) or opposite (indicated by a “−”) direction in the component at the tip of the arrow. Furthermore influence loops—technically known as feedback loops—become apparent and provide further insight into the dynamics of the system’s behaviour.