IfcRelAssigns

Natural language names
deWeist zu - Relation
enRel Assigns
frAssignation
Semantic definitions at the entity
Entity definition

The assignment relationship, IfcRelAssigns, is a generalization of "link" relationships among instances of IfcObject and its various 1st 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.

NOTE  The terms "client" and "supplier" are used in a general concept and do not imply any meaning for implementations of systems (like client-server).
EXAMPLE  A resource may receive information about its nature of representing real building products by establishing a link between IfcResource and IfcBuildingElement (subtype of IfcProduct) through the assignment relationship IfcRelAssignsToResource. The resource is then the client that applies the services of other objects (here building elements) to express the particular view of elements to be consumed as a resource in a process.

The assignment relationship establishs 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.

HISTORY  New entity in IFC2x.
Attribute definitions
#AttributeTypeCardinalityDescription C
5RelatedObjectsIfcObjectDefinitionS[1:?] Related objects, which are assigned to a single object. The type of the single (or relating) object is defined in the subtypes of IfcRelAssigns.X
6RelatedObjectsTypeIfcObjectTypeEnum[0:1] Particular type of the assignment relationship. It can constrain the applicable object types, used within the role of RelatedObjects. X
Formal Propositions
RuleDescription
WR1Rule checks whether the types of the assigned related objects comply with the contraint 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.
Inherited definitions from supertypes
Entity inheritance IfcRelAssignsToActor IfcRelAssignsToControl IfcRelAssignsToGroup IfcRelAssignsToProcess IfcRelAssignsToProduct IfcRelAssignsToResource IfcRelationship IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[0:1] 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.
X
3NameIfcLabel[0:1] 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. X
4DescriptionIfcText[0:1] Optional description, provided for exchanging informative comments.X
IfcRelationship
IfcRelAssigns
5RelatedObjectsIfcObjectDefinitionS[1:?] Related objects, which are assigned to a single object. The type of the single (or relating) object is defined in the subtypes of IfcRelAssigns.X
6RelatedObjectsTypeIfcObjectTypeEnum[0:1] Particular type of the assignment relationship. It can constrain the applicable object types, used within the role of RelatedObjects. X
Definitions applying to Common Use Definitions

Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityCommon Use Definitions
Revision ControlCommon Use Definitions
Formal representations
XSD Specification
 <xs:element name="IfcRelAssigns" type="ifc:IfcRelAssigns" abstract="true" substitutionGroup="ifc:IfcRelationship" nillable="true"/>
 <xs:complexType name="IfcRelAssigns" abstract="true">
  <xs:complexContent>
   <xs:extension base="ifc:IfcRelationship">
    <xs:sequence>
     <xs:element name="RelatedObjects">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcObjectDefinition" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcObjectDefinition"/>
       <xs:attribute ref="ifc:cType" fixed="set"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
    <xs:attribute name="RelatedObjectsType" type="ifc:IfcObjectTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
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;

Link to EXPRESS-G diagram EXPRESS-G diagram

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