Part 1 Perspective and process: learning in and about complex systems; system dynamics in action; the modelling process; structure and behaviour of dynamic systems. Part 2 Tools for systems thinking: causal loop diagrams; stocks and flows; dynamics of stocks and flows; closing the loop - dynamics of simple structures. Part 3 The dynamics of growth: s-shaped growth -epidemics, innovation diffusion and the growth of new products; path dependence and positive feedback. Part 4 Tools for modelling dynamic systems: delays, co-flows and ageing chains; modelling human behaviour - bounded rationality or rational expectations; forecasts and fudge factors - modelling expectation formation. Part 5 Instability and oscillation: supply chains and the origin of oscillations; managing supply chains in manufacturing; the labour supply chain and the origin of business cycles; the invisible hand sometimes shakes - commodity cycles; validation and model testing; appendices.