Technological innovation is accelerating and providing rich tools that can bring the study of real-world problems into mathematics education. System Dynamics (SD) modelling is such a tool that has been successfully used in some secondary school mathematics classes in the US for decades. This chapter uses documentary data to illustrate features that have proven central in the failure and success of innovative programs of SD in precollege education. Moreover, three projects that were successful at infusing SD modelling in the precollege curriculum, each for at least 10 years, will be described along with an enumeration of recommended project characteristics aimed to strengthen future SD projects.