CADIQ validates part and assembly models from all major CAD systems and neutral formats. It identifies problems in an interactive, side-by-side 3D display environment and highlights geometry, features and product structure that has been added, omitted or modified. It identifies changes that can greatly affect reuse in downstream applications such as analysis, manufacturing and data archival. All differences are quickly highlighted with the help of graphic region and mouse controls that can be configured to mimic the user interface of most major CAD systems and thus provide quick productivity to users.