Issue 2164:  The Part - Document relationship (pdm-rtf)
Source:  (, )
Nature:  Uncategorized Issue
Severity: 
Summary: Summary: Problem: The DocumentRevisionRelationship appears to be a general-purpose 
 mechanism for relating Documents to Parts, in that it is many-to-many.
 And yet it specifically relates Part Revisions (PRCL) to Document
 Revisions rather than Document Masters.  It seems that two ideas have
 been mixed here:
     a) the relationship that binds a definitive Document to the Part,
 such that each Revision of the document describes a Revision of the
 part, e.g. the part geometry model; and
     b) a general-purpose relationship that attaches arbitrary 
 Documents to one or more Parts, such as analysis reports, Issue
 documents, design recommendations, etc.
 

Resolution: 
Revised Text: 
Actions taken:
November 4, 1998: received issue
August 24, 1999: closed issue
Discussion: 

End of Annotations:=====
Return-Path: <edbark@cme.nist.gov>
From: Ed Barkmeyer <edbark@cme.nist.gov>
Date: Tue, 3 Nov 1998 17:55:10 -0500 (EST)
To: issues@omg.org
Subject: PDM Enablers issue: the Part - Document relationship 
Cc: pdm-rtf@omg.org
X-Sun-Charset: US-ASCII

Reference: PDM Enablers section 2.7.2 and 2.7.3.4

Problem: The DocumentRevisionRelationship appears to be a
general-purpose 
mechanism for relating Documents to Parts, in that it is many-to-many.
And yet it specifically relates Part Revisions (PRCL) to Document
Revisions rather than Document Masters.  It seems that two ideas have
been mixed here:
    a) the relationship that binds a definitive Document to the Part,
such that each Revision of the document describes a Revision of the
part, e.g. the part geometry model; and
    b) a general-purpose relationship that attaches arbitrary 
Documents to one or more Parts, such as analysis reports, Issue
documents, design recommendations, etc.

It is not clear for concept (b) whether the relationship should be
to the Document Master or to the Document Revision.  But it also
makes no difference, since such relationships are supported directly 
by the PdmFramework::RevisionMasterRelationship and 
PdmFramework::RevisionRelationship respectively.  DocumentMaster,
DocumentRevision and PRCL inherit these thru ItemRevision and they
need not be specifically supported by any PdmPartStructure
relationships.  
The Part - Document relationship in PdmPartStructure should support 
meaning (a) -- definitive documents -- ONLY!  And to that end, the
name 
DocumentRevisionRelationship is misleading, since it does not and
should not inherit from PdmFramework::RevisionRelationship.

Recommendation: 

a. In 2.7.2, modify the UML to rename the "document_revision"
relationship 
and the "doc_rev" role both to "part_document", and modify the
relationship
symbol at the PRCL end to the solid diamond (containment) and the 
cardinality to 1, thus aligning "part_document" with part_data and 
part_structure.

b. Replace section 2.7.3.4 in its entirety with:

"2.7.3.4 PartDocumentRelationship

The PartDocumentRelationship relates the PartRevisionChangeLevel to
the DocumentRevision objects that define aspects of the part.

-------------------------------------------------------------
// PartDocumentRelationship Relationship
//    role : PrclOfDr
//	name : 'PrclOfDr'
//	entity : PartRevisionChangeLevel
//	cardinality : 0..1
//    role : PartDocument
//	name : 'PartDocument'
//	entity: PdmDocumentManagement::DocumentRevision
//	cardinality : 0..unbounded

interface PartDocumentRelationship : 
  PdmFramework::PdmContainmentRelationship { };

interface PartDocumentRelationshipFactory
{
  PartDocumentRelationship create(
	in CosPropertyService::PropertySet property_set,
	in PartRevisionChangeLevel prcl_of_dr,
	in PdmDocumentManagement::DocumentRevision part_document)
      raises (RELATIONSHIP_CREATE_EXCEPTIONS);
};

interface PrclOfDr : PdmFramework::PdmContainsRole {};

interface PartDocument : PdmFramework::PdmContainedInRole {};
-------------------------------------------------------------"


-Ed Barkmeyer

Notes for PDM-RTF:  

1.  The rewrite of 2.7.3.4 really only serves to rename and constrain
the "DocumentRevisionRelationship", but there are a dozen separate
changes.
2.  This may relate to other issues and decisions being taken for 2.7,

but I haven't found them in the spreadsheet.
3.  I believe this change is completely consistent with STEP
product_definition_with_attached_document, but others may disagree.