Proposal to simplify document association

Right now, the document association concept uses an IfcRelAssociatesDocument where the RelatingDocument data type is an IfcDocumentSelect.

This means that you can either relate a Document Reference, which then further references a Document Information, or you can relate a Document Information directly.

This is confusing to users. Especially confusing is that both references and information may contain a potentially conflicting Location attribute.

What are people’s thoughts on this? Can this be simplified to change the document select to always require a document reference? Can doc reference and doc information be merged? (I kinda understand how reference may refer to a particular position within the document, so maybe merging isn’t the right way…)

Bump. A further interpretation is that a document reference cannot exist without an information - the reference defines the scope (i.e. a part, section identifier, or item reference) or a whole (i.e. the document information itself).

In the context of the conflicting Location attribute, this may mean that the reference may specify something like an anchor tag or a sub page, whereas the information may link to the homepage, or cover of the document, etc.

Evidence for this interpretation is given in the diagram below.

The related documentation for IfcConstructionResource has this to say on the matter:

Documents may be published for work plans consisting of schedules, calendars, tasks, and resources. The relationship IfcRelAssociatesDocument may be used to preserve mappings to such document where RelatingDocument points to an IfcDocumentReference and RelatedObjects includes the IfcConstructionResource as shown in Figure 184. IfcDocumentReference.ItemReference identifies the resource within the scope of the document, such as an integer or guid. The IfcDocumentReference.ReferencedDocument corresponds to the document which is uniquely identified by IfcDocumentInformation.DocumentId and/or IfcDocumentInformation.PublicationLocation . Such document mapping allows items in the document to be updated from the building information model and vice-versa.

This paragraph needs updating. ItemReference should now be Identification. Also DocumentId should be Identification. Also PublicationLocation should be Location.

The diagram below also connotes some semantic meaning of the Name attribute, but I unconvinced that this is meaningful given no other evidence in the documentation of semantic importance.

Can anybody confirm this interpretation, and give any thoughts on whether it should be simplified?