ABSTRACT
The system implementation is a phase in engineering work that follows the system design phase. This phase consists of the following two steps: transform a design model into the implementation model and transform the implementation model into a higher-level programming language code. This chapter introduces the component diagrams, which are the means of making implementation models. It illustrates a spectrum of possible finite state machine implementations, including the catalogued state design pattern. The chapter examines the concepts and most important design and implementation details of the finite state machines (FSM) library. The simplest but perhaps still the most frequently used FSM implementation is based on the structural or procedural approach. The State design pattern is one of the approaches to FSM implementation. The original motivation to introduce this design pattern was to support objects that change their behavior as their state changes, exactly what the FSMs do.
