8.17.3.1 IfcPhysicalComplexQuantity

8.17.3.1.1 Semantic definition

The complex physical quantity, IfcPhysicalComplexQuantity, is an entity that holds a set of single quantity measure value (as defined at the subtypes of IfcPhysicalSimpleQuantity), that all apply to a given component or aspect of the element.

A section "Quantity Use Definition" at individual entities as subtypes of IfcBuiltElement gives guidance to the usage of the Name and Discrimination attribute to characterize the complex quantities.

{ .change-ifc2x2}

8.17.3.1.2 Entity inheritance

8.17.3.1.3 Attributes

#	Attribute	Type	Description
IfcPhysicalQuantity (4)
1	Name	IfcLabel	Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.
2	Description	OPTIONAL IfcText	Further explanation that might be given to the quantity.
	HasExternalReferences	SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects	Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity. IFC4-CHANGE New inverse attribute.
	PartOfComplex	SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities	Reference to a physical complex quantity in which the physical quantity may be contained.
Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcPhysicalComplexQuantity (4)
3	HasQuantities	SET [1:?] OF IfcPhysicalQuantity	Set of physical quantities that are grouped by this complex physical quantity according to a given discrimination.
4	Discrimination	IfcLabel	Identification of the discrimination by which this physical complex property is distinguished. Examples of discriminations are 'layer', 'steel bar diameter', etc.
5	Quality	OPTIONAL IfcLabel	Additional indication of a quality of the quantities that are grouped under this physical complex quantity.
6	Usage	OPTIONAL IfcLabel	Additional indication of a usage type of the quantities that are grouped under this physical complex quantity.

Table A

8.17.3.1.4 Formal propositions

Name	Description
NoSelfReference	The IfcPhysicalComplexQuantity should not reference itself within the list of HasQuantities.
`SIZEOF(QUERY(temp <* HasQuantities \| SELF :=: temp)) = 0`
UniqueQuantityNames	Every individual IfcPhysicalQuantity within the set HasQuantities shall have a unique Name attribute value. HISTORY New rule in IFC4
`IfcUniqueQuantityNames(HasQuantities)`

Table B

8.17.3.1.5 Formal representation

ENTITY IfcPhysicalComplexQuantity
SUBTYPE OF (IfcPhysicalQuantity);
HasQuantities : SET [1:?] OF IfcPhysicalQuantity;
Discrimination : IfcLabel;
Quality : OPTIONAL IfcLabel;
Usage : OPTIONAL IfcLabel;
WHERE
NoSelfReference : SIZEOF(QUERY(temp <* HasQuantities | SELF :=: temp)) = 0;
UniqueQuantityNames : IfcUniqueQuantityNames(HasQuantities);
END_ENTITY;

8.17.3.1.6 References

IfcPhysicalQuantity