Transcript Short Presentation About System Dynamics

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
S-shaped Growth
Goal Seeking
S-shaped Growth with Overshoot
Oscillation
Overshoot and Collapse
Exponential Growth
Positive feedback loops generate growth, amplify
deviations, and reinforce change.
System Level
Inflow
Net incr ease rate
Goal Seeking
Negative feedback loops seek balance, equilibrium,
and stasis.
Cor recti ve Acti on
System Level
Discr epancy
Rate of change
Goal
Oscillation
Time delays cause the state of system to constantly
overshoots its goal or equilibrium state, reverses,
then undershoots, and so on.
Cor rective Acti on
System Level
Per ception
Per ception Del ay
Discr epancy
Rate of change
Goal
S-shaped Growth
No real quantity can grow (or decline) forever,
eventually one or more constraints halt the growth.
Net Incr ease Rate
System Level
Resource Adeq uacy
Nor mal Gr owth Rate
Car rying Capacity
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.
Net Incr ease Rate
System Level
Resource Adeq uacy
Del ayed Resource Effect
Nor mal Gr owth Rate
Car rying Capacity
Overshoot and Collapse
The ability of the environment to support a growing
population is eroded or consumed by the
population itself.
Consumption r ate
Car rying Capaci ty
Erosion of Car ryi ng Capacity
Net Incr ease Rate
Nor mal Gr owth Rate
System Level
Resource Adeq uacy
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:
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Management
Government
Economy
Environment
Other dynamic systems