Design patterns: augmenting user intention in parametric design systems

As a family of computing systems intended to facilitate design activities, conventional architectural CAD (Computer Aided Design) software comes in two flavors: drawing tools with symbol libraries and “intelligent” tools that offer component-level design. Both have 2D and 3D realizations. The main downside of these modelling tools is that the components are fabricated by the CAD software vendors, limiting adaptability. With drawing tools, changes and edits on the overall model could impact hundreds of drawings, which have to be checked manually. The “intelligent” solutions overcome this by using object-oriented design to manage dependencies. Parametric modeling software provides designer-level tools for creating and managing dependencies and thus variation. However, the variation supported is mostly continuous and distinctly different alternatives are not part of the model.