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.