REQIF11 — Associations of RelationGroup are limited to XML document scope

ReqIF uses two distinct ways to reference XML identifiers in its XML schema:
1. LOCAL-REF (which is used for XML references within the same XML document) and
2. GLOBAL-REF (which is used for arbitrary, meaning document scope or cross document, XML references).
By mistake, the XML references representing the associations of the RelationGroup type have been made LOCAL-REF references.

The consequence of the mistake is: the source specification and target specification associated to a RelationGroup instance must be contained in the same XML document as the RelationGroup instance, or otherwise the references would be broken and the XML document would not validate against the ReqIF XML schema.

Putting both the source specification, the target specification and the relation group in one XML document can significantly increase the size of XML documents.
Even more important, it would affect almost all exchange processes between companies and their suppliers who use older (pre-OMG) versions of Requirements Interchange Format, as they have been able to exchange single specifications and relation groups separately with these older versions.
This would be a step backwards for these companies and reduce their willingness to use tools that adopt the ReqIF standard.

Resolution:
Simply change two XML attributes in the ReqIF XML schema (lines: <xsd:element name="SPECIFICATION-REF") from LOCAL-REF to GLOBAL-REF as shown below :

Before resolution of the issue:
<xsd:complexType name="RELATION-GROUP">
<xsd:all>
…
<xsd:element maxOccurs="1" minOccurs="1" name="SOURCE-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:LOCAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
…
<xsd:element maxOccurs="1" minOccurs="1" name="TARGET-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:LOCAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
…
</xsd:complexType>

After resolution of the issue:
<xsd:complexType name="RELATION-GROUP">
<xsd:all>
…
<xsd:element maxOccurs="1" minOccurs="1" name="SOURCE-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:GLOBAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
…
<xsd:element maxOccurs="1" minOccurs="1" name="TARGET-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:GLOBAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
… </xsd:complexType>

As a side effect, the XML namespace needs to based on a new date (page 84 of the beta2 specification).

Change two XML attributes in the ReqIF XML schema dtc/10-12-14, (lines:
<xsd:element name="SPECIFICATION-REF") from LOCAL-REF to GLOBAL-REF as
shown below :

Old text:
<xsd:complexType name="RELATION-GROUP">
<xsd:all>
...
<xsd:element maxOccurs="1" minOccurs="1" name="SOURCE-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:LOCAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
...
<xsd:element maxOccurs="1" minOccurs="1" name="TARGET-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:LOCAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
...
</xsd:complexType>

New text:
<xsd:complexType name="RELATION-GROUP">
<xsd:all>
...
<xsd:element maxOccurs="1" minOccurs="1" name="SOURCE-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:GLOBAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
...
<xsd:element maxOccurs="1" minOccurs="1" name="TARGET-SPECIFICATION">
<xsd:complexType>
<xsd:choice maxOccurs="1" minOccurs="1">
<xsd:element name="SPECIFICATION-REF" type="REQIF:GLOBAL-REF"/>
</xsd:choice>
</xsd:complexType>
</xsd:element>
... </xsd:complexType>