Abstract: Recent significant advances in artificial intelligence have led to the emergence of new concepts of soft computing genetic programming, evolutionary engineering, hybrid intelligent systems, and artificial life. EE design relies on evolutionary algorithms to construct or evolve complex systems. This paper is intended to highlight the concept of evolutionary engineering, the motivations behind the use of EE in building complex systems, and a step by step methodology for designing such systems. Finally, we emphasize on a typical example of "Brain Building" design project using EE: the CAM Brain Machine.