Parts & Documents
The figure above illustrates one of the most fundamental concepts of the VEC – the separation of a part and its description. In the VEC a part (PartVersion) does not contain any information about the part, except its PDM Information (PartNumber, PartVersion…). All the information about the technical properties of a part is expressed by a subclass of PartOrUsageRelatedSpecifications (e.g. a WireSpecification). The specifications itsselfes are contained in a DocumentVersion.
This approach enables the VEC to address two scenarios properly:
- The description of a part is changed, but the part itself is not changed (rereleased). This can happen for example if the actual technical properties of the part stay the same, but the description is extended or corrected.
- A document and the contained specifications are describing more than one part (e.g. a drawing for a certain class of terminals). In this case it can happen that the document and the specifications are changed, but not all of the described parts have to be changed (rereleased).