Similette

System Dynamics modelling on the web

Similette is a web-based tool, under development, for building and running System Dynamics models, all inside a standard web browser. You won't need to install any software: you'll just come to this site and start drawing your model diagram, using the intuitive user interface.

'System Dynamics' is the term used to describe a class of models based on the concept of stocks and flows. Stocks represent the amount of some substance; flows define the processes which cause the amount of substance in a stock to increase or decrease. In addition, System Dynamics model have additional ('auxilliary' or 'intermediate' variables) The nice thing about System Dynamics is that models begin life as a diagram (the 'conceptual diagram'), showing the stocks, flows, variables and influence links between them. This is easy to construct. Once you have the diagram, you can then provide values and equations, and your model is ready to run.

Similette is brought to you by the developers of Simile. Simile is a stand-alone program, which is available as a free evaluation version or for purchase: the only difference is the size of model that you can build. Simile also supports System Dynamics modelling, but in addition supports modelling concepts (such as multiple interacting objects) that cannot be modelled in Similette.