Numerous Computer-Aided Design (CAD) tools have been proposed to describe and explore the form and function of an object. Such tools provide sophisticated modeling, analysis and visualization capabilities that greatly enhance the designer's ability to test out a design concept, long before the object is ever constructed. Concurrent engineering refers to the collaborative effort, throughout the design life cycle, of specialists who each focus on a distinct aspect of the system under design, e.g. manufacturability, repairability, aesthetics, etc., in addition to form and function. A truly integrated engineering design system must span the design life cycle (from earliest requirements formulation to system validation) across all aspects of the system.