Major: System Dynamics Slide show brought to you by: WPI Social Science & Policy Studies And WPI System Dynamics Club Author: David Liu

Basic System Behaviors Exponential Growth Goal Seeking Oscillation S-shaped Growth S-shaped Growth with Overshoot Overshoot and Collapse

Exponential Growth Positive feedback loops generate growth, amplify deviations, and reinforce change.

Negative feedback loops seek balance, equilibrium, and stasis. Goal Seeking Negative feedback loops seek balance, equilibrium, and stasis.

Oscillation Time delays cause the state of system to constantly overshoots its goal or equilibrium state, reverses, then undershoots, and so on.

S-shaped Growth No real quantity can grow (or decline) forever, eventually one or more constraints halt the growth.

S-Shaped Growth with Overshoot Time delays in lead to the possibility that the state of the system will overshoot and oscillate around the carrying capacity.

Overshoot and Collapse The ability of the environment to support a growing population is eroded or consumed by the population itself.

Applications of System Dynamics Constructing better mental models Simulating & experimenting with computer models Use the same engineering tools to experiment with and to solve many messy problems of: Management Government Economy Environment Other dynamic systems