latest update: 11 Feb 2015
NOTE - The above diagram may change
In ISO 15926-3 a data model for geometry is defined. That model is an OWL version of ISO 10303-42 that is written in EXPRESS, the modeling language of the ISO 10303 ("STEP") suite of standards.
For the purpose of ISO 15926 (integration, sharing, exchange, and hand-over of plant lifecycle information) the choice has been made to use the technologies of the W3C Semantic Web.
The geom ontology imports the dm ontology.
The OWL version of the Part 3 geometry data model can be found here. (later)