# System Dynamics System Dynamics is a continuous-time simulation paradigm developed by Jay Forrester at MIT in the 1950s. It represents a system as a network of **stocks** (accumulations) and **flows** (rates of change), connected by **feedback loops** that reinforce or balance each other. The model's behaviour emerges from the interaction of these loops, not from individual events or actors. Unlike [[Discrete-Event Simulation (DES)]], which advances time one event at a time, System Dynamics advances time continuously by integrating a system of differential equations derived from the stock-flow structure. It suits problems where the interesting behaviour comes from feedback and delays rather than from individuals, such as population dynamics, supply chains, epidemics, and macro-economic policy. The best-known application is the *Limits to Growth* model commissioned by the Club of Rome in 1972.