What is system dynamics?
System dynamics is a technique for analyzing and modeling (Wikipedia definition) the temporary behavior of systems. It is based on tools extracted from control engineering such as computer identification and simulation, but it is applied to systems that are not necessarily technical: economic, social, ecological, industrial, etc.
In this way, the knowledge of the experts can be structured through mathematical models and the power of computing can be used to support the decision-making progress. It was originally developed in 1950 to help business managers to improve their understanding of industrial processes. Currently, it is used in the public and private sector in policy analysis and design.
In order to know more about this topic you can see these videos (in Spanish) in which Luis Javier Miguel González explains its basics:
You can find the reproduction list with all the videos (in Spanish) here.