Managing Business Complexity is the first complete business- and government-oriented agent-based modeling and simulation resource. It has three purposes: first, to teach readers how to think about ABMS, that is, about agents and their interactions; second, to teach readers how to explain the features and advantages of ABMS to other people; and third, to teach readers how to actually implement ABMS by building agent-based simulations. It is intended to be a complete ABMS resource, accessible to readers who haven’t had any previous experience in building agent-based simulations, or any other kinds of models, for that matter. It is also a collection of ABMS business and government applications resources, all assembled in one place for the first time. In short, Managing Business Complexity addresses who needs ABMS and why, where, and when ABMS can be applied to the everyday business and government problems that surround us, and how specifically to build these powerful agent-based models.