System Dynamics Applications / 4 / 4.1 / 4.1.4

4.1.4 Conceptual Models—Important Aids To Evolving Dynamic Hypotheses

A conceptual model is a ‘straw-man’. It can be torn down and rebuilt as many times as is necessary. We should continue to analyse critically, tear down, and rebuild our straw-man whilst such activities continue to have utility and aid thinking and communicating about dynamic mechanisms of interest.

We might use a straw-man stock-and-flow conceptual model to formalise the current views we hold about cause-and-effect mechanisms. The stock-and-flow diagram is an intellectual device for representing flows and feedback structure essential to developing, refining and testing dynamic hypotheses about the behaviour over time. The coded version of our conceptual stock-and-flow diagram is our computational system dynamics model: through repeated simulation runs using this model we will learn about the relationship between feedback structure of the problem and real-world behaviour.

The basic icons used in stock-and-flow models and their meanings are summarised at Appendix B.