Parametric Design, criteria for its use, and the role of Complexity and Functional Decomposition for the optimal choice of Design Parameters

Modern CAD systems, in particular 3D-CAD, strongly facilitates parametric design. The adaptation of a device or machine for specific user requirements can be done – as far as the generation of drawings is concerned – nearly automatically. Behind parametric design stands a certain design concept. Every feasible parameter combination of the set of free design parameters represents one specific solution of that concept. Nowadays, the main difficulty to set up a reasonable parametric design of a certain system is not anymore its realisation in a CAD program. The most challenging work is the selection of those design parameters for parametric design which are most appropriate. The meaningful range of solutions should correspond to a rather compact set in the parameter space and, the effect of parameter variations should be easy to understand.