IFC 4.3.x development

5.1.3.43 IfcRelationship

5.1.3.43.1 Semantic definitions at the entity

IfcRelationship is the abstract generalization of all objectified relationships in IFC. Objectified relationships are the preferred way to handle relationships among objects. This allows to keep relationship specific properties directly at the relationship and opens the possibility to later handle relationship specific behavior.

There are two different types of relationships, 1-to-1 relationships and 1-to-many relationship. used within the subtypes of IfcRelationship. The following convention applies to all subtypes:

  • The two sides of the objectified relationship are named Relating+<name of relating object> and Related+<name of related object>
  • In case of the 1-to-many relationship, the related side of the relationship shall be an aggregate being a set 1:N

HISTORY  New entity in IFC1.0.

#Attribute Type Description
IfcRoot
1GlobalId IfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world.
2OwnerHistoryOPTIONAL IfcOwnerHistoryAssignment 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.
3Name 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.
4Description OPTIONAL IfcText Optional description, provided for exchanging informative comments.

5.1.3.43.1 Entity inheritance

dot_inheritance IfcRelationship_children 5 more... IfcRelationship IfcRelationship IfcRelationship_children->IfcRelationship IfcRoot IfcRoot IfcRelationship->IfcRoot IfcObjectDefinition IfcObjectDefinition IfcObjectDefinition->IfcRoot IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot

5.1.3.43.2 Definitions applying to General Usage

5.1.3.43.2.1 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

5.1.3.43.2.2 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

5.1.3.43.3 Formal representations

ENTITY IfcRelationship
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcRelAssigns
	,IfcRelAssociates
	,IfcRelConnects
	,IfcRelDeclares
	,IfcRelDecomposes
	,IfcRelDefines))
 SUBTYPE OF (IfcRoot);
END_ENTITY;