Incorporating knowledge of geometric dimensioning and tolerancing into a feature-based CAD system

A system is described which aids a designer in assigning dimensions and tolerances to designs of mechanical parts. The system is constructed using an object-oriented approach. Designs are created using geometric features such as slots and holes. For each feature, there is knowledge about the object regarding appropriate ways to dimension and tolerance that feature. The tolerancing system used is unambiguous and is similar to geometric dimensioning and tolerancing (GD&T), the standard system used in industrial practice