1. Bathtub Water Level Model
Water Supply
Water Level
Sewer
Faucet
Drain
Water pressure
“Cloggage”
Cloud – input/output that doesn’t affect model
Converter – constant used within the model
Flow – causes conditions to change
Stock – tells what conditions are
Link – connects two parts of a model
Key to Symbols

2. Compound Interest Model
Bank Balance
Earning Interest R
The R means that this is a self-reinforcing or “positive” feedback loop which makes the result exponential
Interest Rate
Cloud – input/output that doesn’t affect model
Converter – constant used within the model
Flow – causes conditions to change
Stock – tells what conditions are
Link – connects two parts of a model
Key to Symbols

3. Compound Interest Model
Can be represented by a relatively simple equation
Can also be shown graphically
Where:
A – Final amount
P – Principle amount
r – Interest Rate
t – Time (years)

7. Increased Resolution Requires Increased Computing Resources
Rule of thumb:
10X more CPU
for a doubling of
resolution

8. Sources Slide 1 and 2 Slide 3 Slide 4 Slide 5 Slide 6 Slide 7
“An Introduction to Systems Thinking”, High Performance Systems, Inc.
Slide 3
Slide 4
Slide 5
Slide 6
Slide 7