After a summary of the architecture proposed by Daniel Krob, president of CESAMES in Paris, France, the book focuses on the sensor and effector equipment that routes and converts the system's information to the place where it is processed. These are the equivalent of the system's sense organs. It also analyzes the roots of complexity from the perspective of combinatorics: in real systems, everything comes down to cases and/or configurations being validated in greater or lesser numbers, but which must be kept under control. This book presents two case studies, giving a global vision of complexity. Finally, it presents a prospective approach that brings the engineering of artificial systems closer to that of biological systems, based on first-hand information provided by Philippe Kourilsky, Emeritus Professor at the Collège de France.