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Escaping the Complexity Dilemma
Barry Newell & Katrina ProustThe Australian National University
The Complexity Dilemma
1. A feedback system is a set of parts (elements, actors) that interact to constrain each other’s behaviour.
2. The behaviour of such a system emerges from the interactions between its parts.
3. Therefore, you can’t optimise the behaviour of the system by optimising the behaviour of the parts taken in isolation.
4. You have to study the system as a whole.
5. But, when you try to do this, you are overwhelmed by the complexity of the system. The behaviour appears to be unmanageable.
Escaping the Complexity Dilemma
One way to escape the complexity dilemma is to look for shared features or attributes between things which, at first sight, seem to be very different.
For example, if a number of apparently disparate behaviours can be shown to be just different versions of a single behaviour, there can be a significant reduction in the apparent complexity of the observed world.
1. Constructing freeways2. Substance abuse3. The war on terror4. The war on drugs 5. Taxing alcopops6. Urban renewal 7. Constructing flood-control levees8. Engineering the climate 9. Intensive irrigation development10. Spraying ragweed with broad spectrum herbicides* 11. Using mould ‘killers’ in bathrooms*12. Introducing shrimp to feed freshwater salmon*13. Planting wheat on the Great Plains*
The Challenge ActivitiesIn system dynamics
terms, your challenge was “construct a generic dynamic
hypothesis”.
System dynamicists construct models, mental or formal, that explain why things behave the way that they do). Causal theories.
All such theories attempt to isolate invariant behaviours in the world. That is, behaviours that are observed in many different contexts and at many different times. Generic behaviours.
All such theories attempt to provide simple explanations for these generic behaviours.Powerful explanations.
System Dynamics
System Dynamics
“The feedback loop is the fundamental
building block of system dynamics
models, and is the basic unit of analysis
and communication of system
behaviour.”
George Richardson, 1991, Feedback Thought in
Social Science and Systems Theory, p. 4.
System Dynamics
Only two types of feedback:
Reinforcing Balancing Positive Negative
System Dynamics
Only two types of feedback:
Positive feedback is not necessarily good.Negative feedback is not necessarily bad.
System Dynamics
Only two types of feedback:
Feedback can cause counterintuitive behaviour.
Detail Complexity (Combinatorial)
Examples: Scheduling commercial aircraft movements at a large airport. Scheduling classes into classrooms, particularly when there is significant course flexibility.
Dynamic Complexity (Feedback)
Example: The Ragweed Problem
System Dynamics
Only two types of complexity:
The Ragweed Problem
The Ragweed Problem
But … leads to more ragweed next year. Why?
The Ragweed Problem
The Mould Problem
It’s habit forming
CHOICEMagazine
Shonky Awards2012
The Mould Problem
Spencer et al. 1991, BioScience, 41, 14-21.
Salmon and Shrimp
Salmon and Shrimp
Wheat on the Great Plains
System Archetype
Fixes That Fail
Generic Structure
Generic Structure
Fixes That Fail
System Archetype
Signature Behaviour
Fixes That Fail
System Archetype
Meadows considers System Archetypes to be “system traps and opportunities”.
Traps – because they can cause unexpected outcomes, such as ‘fixes that fail’ – barriers to effective policy implementation.
Opportunities – because, once recognised, they can help isolate powerful ‘leverage points’ – places in a system where small pushes can lead to large changes.
System Traps and Opportunities
Meadows, D.H., 2009, Thinking in Systems (Earthscan: London)
Leverage Point
Fixes That Fail
Leverage Point
Fixes That Fail
System Archetype
Fixes That Fail Template 1
System Archetype
Fixes That Fail Template 2
The Fixes That Fail archetype can be used to structure a discussion of the similarities of the activities on the challenge list.
1. Working in groups, develop an explanation of the failure of one or more of the ‘fixes’ (Activity 1 to 9, inclusive). You can use the templates provided.
2. Select one of your archetypes for presentation and discussion.
3. Nominate a group member to make the presentation.
Apply the Archetype
Further Reading
Meadows, D.H., 2009, Thinking in Systems: A Primer (Earthscan: London). A good general introduction to system thinking and system dynamics. Easy reading.
Senge, P., 1990, The Fifth Discipline: The Art and Practice of The Learning Organization (Random House: Sydney). The first published discussion of system archetypes, which he calls “Nature’s Templates.” Easy reading.
Sterman, J.D., 2000, Business Dynamics: Systems Thinking and Modeling for a Complex World (Irwin McGraw-Hill: Boston). A thorough discussion. Do not be misled by the word ‘business’ in the title—this is a solid textbook that will be valuable to readers in all disciplines. ~1000 pages.
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