5.1.3.19 IfcQuantitySet

ABSTRACT This definition may not be instantiated

5.1.3.19.1 Semantic definition

IfcQuantitySet is the the abstract supertype for all quantity sets attached to objects. The quantity set is a container class that holds the individual quantities within a quantity tree. These quantities are interpreted according to their name attribute and classified according to their measure type. Some quantity sets are included in the IFC specification and have a predefined set of quantities indicated by assigning a significant name. These quantity sets are listed as "quantity sets" within this specification. Quantity sets applicable to certain objects are listed in the object specification.

An IfcPropertySetTemplate may define the underlying structure, i.e. the required name, the applicable object or object types to which the quantity set can be attached, and the individual quantities that maybe included. Quantity sets are related to other objects by using the relationship object that refers to the corresponding object:

Occurrence Object: IfcRelDefinesByProperties using the inverse attribute DefinesOccurrence.
Type Object: using a direct link by inverse attribute DefinesType.
Underlying template: IfcRelDefinesByTemplate using the inverse attribute IsDefinedBy.
External reference: subtypes of IfcRelAssociates are used to provide a link to a classification system, or external library providing further reference to the quantity set. Accessible by inverse attribute HasAssociations.

5.1.3.19.2 Entity inheritance

5.1.3.19.3 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.
IfcPropertyDefinition (2)
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	No description available.
	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 5.1.3.19.A

5.1.3.19.4 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.
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Table 5.1.3.19.B

5.1.3.19.5 Formal representation

ENTITY IfcQuantitySet
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcElementQuantity))
 SUBTYPE OF (IfcPropertySetDefinition);
END_ENTITY;