5.1.3.21 IfcRelAssigns

ABSTRACT This definition may not be instantiated

5.1.3.21.1 Semantic definition

The assignment relationship, IfcRelAssigns, is a generalization of "link" relationships among instances of IfcObject and its various 1^st^ level subtypes. A link denotes the specific association through which one object (the client) applies the services of other objects (the suppliers), or through which one object may navigate to other objects.

The client is denoted as the relating object and is established at the level of the specific, instantiable subtypes of IfcRelAssigns. The suppliers are denoted as the related objects and they are established by the RelatedObjects attribute.

The assignment relationship establishes a bi-directional relationship among the participating objects and does not imply any dependency. The subtypes of IfcRelAssigns establishes the particular semantic meaning of the assignment relationship.

5.1.3.21.2 Entity inheritance

- IfcRoot

5.1.3.21.3 Attributes

#	Attribute	Type	Description
IfcRoot (4)
1	GlobalId	IfcGloballyUniqueId	Assignment of a globally unique identifier within the entire software world.
2	OwnerHistory	OPTIONAL IfcOwnerHistory	Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE only the last modification in stored - either as addition, deletion or modification. IFC4-CHANGE The attribute has been changed to be OPTIONAL.
3	Name	OPTIONAL IfcLabel	Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.
4	Description	OPTIONAL IfcText	Optional description, provided for exchanging informative comments.
Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcRelAssigns (2)
5	RelatedObjects	SET [1:?] OF IfcObjectDefinition	Related objects, which are assigned to a single object. The type of the single (or relating) object is defined in the subtypes of IfcRelAssigns.
6	RelatedObjectsType	OPTIONAL IfcObjectTypeEnum	Particular type of the assignment relationship. It can constrain the applicable object types, used within the role of RelatedObjects. IFC4-CHANGE The attribute is deprecated and shall no longer be used. A NIL value should always be assigned.

Table 5.1.3.21.A

5.1.3.21.4 Formal propositions

Name	Description
WR1	Rule checks whether the types of the assigned related objects comply with the constraint given by the RelatedObjectsType. The rule is important for constraint checks at subtypes of IfcRelAssigns or at subtypes of IfcObject, which refers to assignment relationships through the inverse HasAssignments relation.
`IfcCorrectObjectAssignment(RelatedObjectsType, RelatedObjects)`

Table 5.1.3.21.B

5.1.3.21.5 Concept usage

Concept	Usage	Description
IfcRoot (2)
Revision Control	General	Ownership, history, and merge state is captured using IfcOwnerHistory.
Software Identity	General	IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
Click to show 2 hidden inherited concepts Click to hide 2 inherited concepts

Table 5.1.3.21.C

5.1.3.21.6 Formal representation

ENTITY IfcRelAssigns
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcRelAssignsToActor
	,IfcRelAssignsToControl
	,IfcRelAssignsToGroup
	,IfcRelAssignsToProcess
	,IfcRelAssignsToProduct
	,IfcRelAssignsToResource))
 SUBTYPE OF (IfcRelationship);
	RelatedObjects : SET [1:?] OF IfcObjectDefinition;
	RelatedObjectsType : OPTIONAL IfcObjectTypeEnum;
 WHERE
	WR1 : IfcCorrectObjectAssignment(RelatedObjectsType, RelatedObjects);
END_ENTITY;