System Archetypes

1
System Archetypes

• Sources Jay Forrester, Donella Meadows, Peter
  Senge, Dan Kim, William Braun, and others.

2
Forresters 1968 List(Urban Dynamics, Chapter 6
Notes on Complex Systems)

• Counterintuive behavior
• Insensitivity to parameter changes
• Resistance to policy changes
• Control through influence points
• Corrective programs counteracted by the system
• Long-term versus short-term response
• Drift to low performance

3
Dana Meadows 1980 List(Whole Earth Models
Systems, Coevolution Quarterly)

• Policy resistance
• Drift to low performance
• Addiction
• Official addiction shifting the burden to the
  intervener
• High leverage, wrong direction

4
Danas Recommendations for Global Policy

• Respectful of the system
• Responsible for the systems behavior
• Experimental
• Attentive to the system as a whole
• Attentive to the long term
• Comprehensive
• No part of the human race is really separate
  either from other human beings or from the global
  ecosystem. We all rise or fall together.

5
Brauns List

• Limits to Growth (aka Limits to Success)
• Shifting the Burden
• Eroding Goals
• Escalation
• Success to the Successful
• Tragedy of the Commons
• Fixes that Fail
• Growth and Underinvestment
• Accidental Adversaries
• Attractiveness Principle

6
Limits to growth Limits to success
7
Shifting the burden

• Examples?

8
Eroding goals

• What famous model does this come from?

9
Escalation
10
Success to the successful
11
Tragedy of the commons

• Not clear one can build a model exhibiting the
  phenomenon of the Tragedy of the Commons from
  this structure.

12
Fixes that fail

• What are the stocks?

13
Growth and underinvestment
14
Accidental adversaries

• Ive never seen this applied.

15
Attractiveness principle
16
How Braun puts them together
17
Things to observe

• Forresters list comes directly from
  simulation-based studies
• Meadowss list is similarly based on empirical
  experience with formal models
• Brauns list (adapted from Senge and Kim) is
  distant from formal models.
• Some archetypes are easy to model.
• Some archetypes are hard to model.

18
A stock-and-flow archetype(Andersen and
Richardson, various interventions)