Computer-aided design (CAD) appears more than ever as a complex process uniting different activities of different natures: geometric modeling, synthesis, analysis, simulation, calculation, manufacturing, etc.. A CAD system must not only allow the creation of a considerable quantity of objects (surface, volume, mesh, dimensioning, tolerance, effort, ...), but also the management of the links between these objects. These relationships between objects can be in the form of geometric, technological, economic or even administrative constraints. The data model of such a system must therefore be able to manage the evolution of these objects and the propagation of constraints and support possible changes in design parameters. More and more, the integration of different CAD, calculation and simulation tools is necessary. This book presents an original contribution to the integration of CAD and Computation_simulation aspects based on numerical models developed on the basis of examples in order to show the generalization of the proposed concepts to an industrial context.