This book introduces DAVID (Draw A Vensim Initial Draft), a cutting-edge tool that takes the capabilities of ChatGPT a step further. DAVID transforms a textual description of a problem into a fully functional Vensim model. By integrating with ChatGPT o1, DAVID generates the necessary equations and variables, and then compiles them into an executable Vensim file. In essence, DAVID automates the entire process, turning a simple text input into a complete, operational model ready for simulation.