5.1.3.15 IfcPropertySetDefinition

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ABSTRACT This definition may not be instantiated

5.1.3.15.1 Semantic definition

IfcPropertySetDefinition is a generalization of all individual property sets that can be assigned to an object or type object. The property set definition can be either:

Dynamically extendable property sets - IfcPropertySet, a set of properties for which the IFC specification only provides a kind of "meta model", to be further declared by agreement. This means no entity definition of the properties exists within the IFC specification. The declaration is done by assigning a significant string value to the Name attribute of the entity as defined in the entity IfcPropertySet and at each subtype of IfcProperty, referenced by the property set. Dynamically defined property sets may have an underlying template provided by IfcPropertySetTemplate.
Statically defined property sets - IfcPreDefinedPropertySet, a property set entity that exists within the IFC specification. The semantic meaning of each statically defined property set is declared by its entity type and the meaning of the properties is defined by the name and data type of the explicit attribute representing it.

Property set definitions define information that is shared among multiple instances of objects, either object occurrences or object types. IfcPropertySetDefinition's (by their instantiable subtypes) can participate within the following relationships:

Assignment to object types - an DefinesType direct relationship to IfcTypeObject that applies the property set, with all included properties, to the object type. Those properties apply to all object occurrences having the same object type.
Assignment to object occurrences - an DefinesOccurrence relationship to IfcRelDefinesByProperties that applies the property set, with all included properties, to the object occurrence.

5.1.3.15.2 Entity inheritance

5.1.3.15.3 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 is 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.
IfcPropertyDefinition (2)
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	Reference to the relationship IfcRelDeclares and thus to the IfcProject or IfcProjectLibrary.
	HasAssociations	SET [0:?] OF IfcRelAssociates FOR RelatedObjects	Reference to the relationship IfcRelAssociates and thus to those externally defined concepts, like classifications, documents, or library information, which are associated to the property definition.
Click to show 6 hidden inherited attributes Click to hide 6 inherited attributes
IfcPropertySetDefinition (3)
	DefinesType	SET [0:?] OF IfcTypeObject FOR HasPropertySets	The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object. NOTE The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard. IFC4-CHANGE The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.
	IsDefinedBy	SET [0:?] OF IfcRelDefinesByTemplate FOR RelatedPropertySets	Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties. IFC4-CHANGE New inverse relationship, change made with upward compatibility for file based exchange.
	DefinesOccurrence	SET [0:?] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition	Reference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties. IFC4-CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.

Table 5.1.3.15.A

5.1.3.15.4 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 5.1.3.15.B

5.1.3.15.5 Formal representation

ENTITY IfcPropertySetDefinition
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcPreDefinedPropertySet
	,IfcPropertySet
	,IfcQuantitySet))
 SUBTYPE OF (IfcPropertyDefinition);
 INVERSE
	DefinesType : SET [0:?] OF IfcTypeObject FOR HasPropertySets;
	IsDefinedBy : SET [0:?] OF IfcRelDefinesByTemplate FOR RelatedPropertySets;
	DefinesOccurrence : SET [0:?] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;
END_ENTITY;