1.3 MODELS FOR ENGINEERING DESIGN
The common ground for the stages of preliminary and formal design, as well as between the various domains of engineering, must be structured in language ideally common to all engineering domains. Breakdowns in the design and quality of a part throughout the engineering and manufacturing of that part is often due to lack of clear communication between the phases. For example, measurement units of centimeters may be substituted by millimeters. The designer's top of a molded piece may be the bottom to a molding engineering who views the part for a mold design. It is evident that the one aspect truly common throughout all phases of engineering is the product's artifact of design. Necessarily, the design is represented as a geometric CAD model, and is placed at the center of a concurrent engineering environment.
The consideration of design as an artifact around which the processes of the manufacturing environment swirl is in direct contrast to the information flow model, which considers the engineering process as a series of transformations of representations. The object technology zeitgeist of the software programming environment of the late 1980's and early 1990's is applicable in this situation. Design-as-an-artifact allows a conceptual base with which to focus concurrent engineering issues, as opposed to design-as-a-process, where the issues tend to get tangled with multiple procedures and multiple models.
The paradigm shift from procedural, information flows to an object-oriented design model is profound. But placing the design artifact at the center of attention is not enough. One must look at the nature of the artifact itself. As stated before, the ground between engineering domains, as well as engineering phases, is structured by language. Language is asserted to be a social convention that provides a common background for communicating parties. Design may simultaneously be used as an artifact for computation, like a mathematical function, or as a means of communication, like a page of text.