A New ISO 10303 (STEP) Resource for Modeling Parameterization and Constraints

ISO 10303 (STEP) is a standard for the electronic exchange of product life-cycle data. It has been continually expanded by the addition of new capabilities since its first release by ISO in 1994. Until now, the standard has not been capable of exchanging models with parameterization and constraints such as those commonly generated by modern CAD systems. This makes it difficult to modify a model for any purpose following an exchange. However, new STEP resources have been developed to rectify this situation, and the paper reports on the the first of them to reach International Standard status. It provides the capability to associate explicitly represented parameterization and constraint information with CAD models. The primary application areas are in the 2D profiles or sketches that are inherent in many CAD model constructional procedures, in the positioning and orientation of features in 3D models and in the positioning and orientation of assembly components. Other complementary new STEP resources are briefly discussed at the end of the paper.