1. Copyright, 1995-2002 1 Invitation to Research SYSTEMS THINKING Roger Clarke, Xamax Consultancy, Canberra Visiting Professor, CSIS, Uni of Hong Kong Visiting Fellow, Australian National University http://www.anu.edu.au/people/Roger.Clarke/......Res /15-Sys.ppt ebs, 16-20 January 2003

2. Copyright, 1995-2002 2 Agenda Systems Models Cybernetics Complexity of: System Model Behaviour

3. Copyright, 1995-2002 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 mammals cardio-vascular and digestive systems) be related hierarchically (e.g. corpuscles within blood within the cardio-vascular system)

4. Copyright, 1995-2002 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. Copyright, 1995-2002 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. Copyright, 1995-2002 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. Copyright, 1995-2002 7 Simple Process Model

8. Copyright, 1995-2002 8 Process Model with Controller

9. Copyright, 1995-2002 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. Copyright, 1995-2002 10 Levels of Discourse About Systems (Boulding) FrameworkAnatomy Balanced DynamicClockwork 1st-Order ControlThermostat Open, Self-MaintainingCell (in Biology) Genetic-SocietalPlant Self-Aware, PurposiveAnimal (& Orgn?) Self-ConsciousHuman...