1.1 Introduction

This book deals with the subject of simulation as it applies to the process of designing, developing, and testing complex dynamic embedded systems. A dynamic system ^[1]has behavior that is described by differential equations (for continuous-time systems) or by difference equations (for discrete-time systems). Dynamic embedded systems are dynamic systems that use computing resources to control their dynamic behavior. The number of applications for dynamic embedded systems is steadily increasing, and includes safety-critical systems and those that have the potential to cause large financial loss in the event of system failure. Because of these risks, system developers must provide a high level of assurance that the system hardware and software designs and implementations are free from serious errors. It is more important than ever to use development tools and processes that reduce the potential for serious design problems which may remain undetected until late in the development cycle or after the product is in customer hands.

Simulation is an approach that can significantly accelerate the product development cycle and provide higher quality in the final system. A simulation contains a set of mathematical models of one or more dynamic systems and the interactions between those systems and their environment. During execution, the simulation advances through time and solves the equations for all the models at each point in time. The equations that describe the behavior of complex systems are complex themselves so the approach used in simulation is often the only way to solve...