A model is a simplified or partial representation of reality, defined in order to accomplish a task or to reach an agreement. It is based on an original system reflecting the relevant selection of the original system properties. The model is the central artifact of software development, it includes the documentation, static analysis, rapid prototyping, automated testing, refactoring, transformation and code generation. The increasing complexity of software in engineering applications leads to problems in the software development like production delay, wrong functionalities, software poorly documented or commented. Modelling allows to increase productivity, efficiency, reusability, improve portability of the software, easy to test.