1.1. Modeling systems
A system is designed to provide one or more services. It is made up of hardware, software and human resources, with the aim to satisfy a precise, well-defined need. Such systems abound in the history of science. Thanks to accumulating experience, technological progress and ever improving modeling approaches, methods to develop these are constantly gaining efficiency. The description of a system potentially involves various notions about its components, their aggregation and their interactions with each other and with the system’s environment.
A system usually consists of a set of interdependent entities whose functions are fully specified. The system is completely characterized according to an equational or functional approach, in an iterative top-down or bottom-up process. The process is top-down in an analytical approach whereby each part can be broken down into smaller subparts that are complete sub-systems themselves. Conversely, when the approach consists of building a system up from the basis of simpler sub-systems, the iterative process is called bottom-up. The system’s realization and potential evolution are predetermined in a strict, narrow field, and its functionalities can pertain to various applicative areas such as electricity, electronics, computer science, mechanics, etc.
Because of the advances being made in system design as well as in information and communication technologies, there is a tendency to design