1. Causal Loop Diagrams A Primer Jeff Wasbes Research Works, Inc.

2. Presentation Outline Introduction Mechanics Some tips
The what and the why…
Mechanics
The how…
Some tips
On good diagramming practice

3. Introduction What are Causal Loop Diagrams? They are useful for
An important tool for representing the feedback structure of systems
They are useful for
Quickly capturing hypotheses about the causes of dynamics
Eliciting and capturing the mental models of individuals or teams
Communicating important feedbacks you think might be responsible for a problem

4. Constructing a Simple Diagram
All objects (variables) are nouns
All links show causality +
Park Maintenance
Litter
All links have Polarity
Constructing a Simple Diagram

5. A variable increases to an amount more than it would have otherwise been…
Net Birth Rate
Time
A variable decreases to an amount less than it would have otherwise been…
Net Birth Rate
Time

6. Constructing a Simple Diagram
All objects (variables) are nouns
All links show causality +
(-) Clean Up Effort
Park Maintenance
Litter
All links have Polarity -
All loops have polarity
…and the important ones should have names
Constructing a Simple Diagram

7. Refuse Carrying Capacity
What story does this diagram tell? +
(-) Clean Up Effort +
Park Maintenance
Litter
Show important delays in the system -
(+)
Overflow + + =
Overflow
Refuse -
Refuse Carrying Capacity

8. Refuse Carrying Capacity+
Use
(+)
Public Engagement +
Perceived Park Condition - +
Pressure to Maintain =
(-) Clean Up Effort + +
Park Maintenance
Litter - +
(+)
Overflow
Refuse Removal + +
Overflow =
Refuse -
Refuse Carrying Capacity -

9. Refuse Carrying Capacity+
Use
(+)
Public Engagement +
Minimize Clutter
Perceived Park Condition - +
Pressure to Maintain
Organize your diagram to minimize crossed lines =
(-) Clean Up Effort + +
Park Maintenance
Litter -
Model the System, not the Problem +
(+)
Overflow
Refuse Removal
Vensim PLE:
A free software for formulating SD models + +
Overflow =
Refuse -
Refuse Carrying Capacity -

10. For follow-up or questions
Jeff Wasbes
Thank you!