1. Invitation to Research SYSTEMS THINKING Roger Clarke, Xamax Consultancy, Canberra Visiting Professor, CSIS, Uni of Hong Kong Visiting Fellow, Australian National University Res /15-Sys.ppt ebs, January 2003

2. Agenda Systems Models Cybernetics Complexity of: System Model
Behaviour

3. A System A set of interacting Real-World Entities
Interacts with its Environment across its Boundary
Entities within a System:
gather inputs via Sensors
transmit outputs via Effectors
interact with one another via Interfaces
Systems may:
exist at the same level (e.g. an mammal’s cardio-vascular and digestive systems)
be related hierarchically (e.g. corpuscles within blood within the cardio-vascular system)

4. System Characteristics
Degree of Closedness/Openness to external Stimuli or Triggers
Entropy The tendency to lose energy and order
Negentropy The importation of energy to sustain order
Unguidedness cf. Purposiveness
Adaptiveness/Learning The ability to change as a result of stimuli

5. A Model An Abstract-World Representation of a Real-World System
Iconic or Symbolic/Mathematical
Capable of being:
viewed (e.g. a map
manipulated (e.g. a model aircraft in a wind-tunnel)
in ways that the System cannot be
Necessarily (greatly) simplified
‘The only reliable model of a real-world system is the system itself’ (Pratchett)

6. Categories of Models Deterministic Models – Automata
Computable by Analytical Methods
Too Complex to Compute, hence Requiring Numerical Methods
Probabilistic Models
Non-Deterministic / Stochastic Models
Entities exercising Self-Determination / Free Will e.g. Humans and Organisations

7. Simple Process Model

8. Process Model with Controller

9. Cybernetics Control Loop:
Inputs or Process Parameters changed as a result of measurement of Outputs
Feedback: Positive / Reinforcing or Negative / Retardent
Static Equilibrium / Steady-State cf. Dynamic Equilibrium / Homeostasis
Delays, Control Limits, Tolerances
=> Hunting / Hysteresis, Over-Correction
Feedforward
Tiered Control Loops exhibit Complex Behaviour

10. Levels of Discourse About Systems (Boulding)
Framework Anatomy
Balanced Dynamic Clockwork
1st-Order Control Thermostat
Open, Self-Maintaining Cell (in Biology)
Genetic-Societal Plant
Self-Aware, Purposive Animal (& Orgn?)
Self-Conscious Human
...