Rich Pictures, Causal Loop Diagrams and Stock & Flow Simulation Models are the three types of models most commonly used.

CLD of Eric Wolstenholme Syst. Dyn. Rev. 23, 371–389, (2007) See IM-1008 for a stock flow version.

All you wanted to do was put a bird feeder in your yard to attract birds and make for a more pleasant morning. And...

The structure responsible for rabbit population growth.

The structure responsible for rabbit population growth.

All you wanted to do was put a bird feeder in your yard to attract birds.

What do activities of these images have in common?

Balancing Loop with Stock & Flow Diagram.

Balancing Loop with Stock & Flow Diagram.

When one undertakes to create a model there are a number of guidelines that are considered essential for consideration if there is to be a success with the model.

What do activities of these images have in common?

What do activities of these images have in common?

This common archetype of systems that include relapse or recidivism allows exploration of the unintended effects of increasing upstream capacity and swamping downstream capacity. The increase in the relapse rate eventually returns to swamp upstream capacity as well. A social welfare example, based on a TANF case study, from How Small System Dynamics Models Can Help the Policy Process. N. Ghaffarzadegan, J. Lyneis, GP Richardson. System Dynamics Review 27,1 (2011) 22-44 Conference version at http://bit.ly/HlxtZj

Balancing Loop with Stock & Flow Diagram.

The structure responsible for rabbit population growth.

All you wanted to do was put a bird feeder in your yard to attract birds and make for a more pleasant morning. And...

Introduce the concept of modeling and simulation.

Balancing Loop with Stock & Flow Diagram.

A small change in one variable can have a marked impact on multiple variables. Run the model [quits change] = 0  and consider the output. What happens if  you change [quits change] = 5. Run the model to find out. Was the change what you expected?

Balancing Loop with Stock & Flow Diagram.

What do activities of these images have in common?

What do activities of these images have in common?

All the following have a common characteristic.

While these pictures represent very different things there is a common essence.