A System Dynamics diagram shows the storages (stocks) and flows of material in some system, and the factors that influence the rates of flow. It is usually a cosmetic interface for building mathematical models -- you provide values and equations for the stocks and flows, and appropriate software can then simulate the system's behaiour.
The diagram has two types of link: flow links and influence links. In additon to the node attached to each flow, there are 3 types of node:
The conventional user interface for building System Dynamics diagrams is modal -- you select a tool in the toolbar, then either click in an empty part of the diagram to add a node or drag from one node to another to add a link. That is the approach used in this example. Note that you need to click on the Pointer tool to revert to the normal mode.
This sample is based on a prototype developed by Robert Muetzelfeldt.