8.3.3.2 IfcMetric

8.3.3.2.1 Semantic definition

An IfcMetric is used to capture quantitative resultant metrics that can be applied to objectives.

IfcMetric is a subtype of IfcConstraint and may be associated with any subtype of IfcRoot through the IfcRelAssociatesConstraint relationship in the IfcControlExtension schema, or may be associated with IfcProperty by IfcResourceConstraintRelationship.

The aim of IfcMetric is to capture the quantitative aspects of a constraint.

Figure 8.3.3.2.A — An example user defined constraint.

8.3.3.2.2 Entity inheritance

8.3.3.2.3 Attributes

#	Attribute	Type	Description
IfcConstraint (9)
1	Name	IfcLabel	A human-readable name to be used for the constraint.
2	Description	OPTIONAL IfcText	A human-readable description that may apply additional information about a constraint.
3	ConstraintGrade	IfcConstraintEnum	Enumeration that qualifies the type of constraint.
4	ConstraintSource	OPTIONAL IfcLabel	Any source material, such as a code or standard, from which the constraint originated.
5	CreatingActor	OPTIONAL IfcActorSelect	Person and/or organization that has created the constraint.
6	CreationTime	OPTIONAL IfcDateTime	Time when information specifying the constraint instance was created.
7	UserDefinedGrade	OPTIONAL IfcLabel	Allows for specification of user defined grade of the constraint beyond the enumeration values (hard, soft, advisory) provided by ConstraintGrade attribute of type IfcConstraintEnum. When a value is provided for attribute UserDefinedGrade in parallel the attribute ConstraintGrade shall have enumeration value USERDEFINED.
	HasExternalReferences	SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects	Reference to an external references, e.g. library, classification, or document information, that are associated to the constraint. IFC4-CHANGE New inverse attribute.
	PropertiesForConstraint	SET [0:?] OF IfcResourceConstraintRelationship FOR RelatingConstraint	Reference to the properties to which the constraint is applied.
Click to show 9 hidden inherited attributes Click to hide 9 inherited attributes
IfcMetric (4)
8	Benchmark	IfcBenchmarkEnum	Enumeration that identifies the type of benchmark data.
9	ValueSource	OPTIONAL IfcLabel	Reference source for data values. If DataValue refers to an IfcTable, this attribute identifies the relevant column identified by IfcTableColumn.Identifier.
10	DataValue	OPTIONAL IfcMetricValueSelect	The value to be compared on associated objects. A null value indicates comparison to null. IFC4-ADD1 CHANGE This attribute is now optional.
11	ReferencePath	OPTIONAL IfcReference	Optional path to an attribute to be constrained on associated objects. If provided, the metric may be validated by resolving the path to the current value on associated object(s), and comparing such value with DataValue according to the Benchmark.

Table 8.3.3.2.B

8.3.3.2.4 Formal representation

ENTITY IfcMetric
 SUBTYPE OF (IfcConstraint);
	Benchmark : IfcBenchmarkEnum;
	ValueSource : OPTIONAL IfcLabel;
	DataValue : OPTIONAL IfcMetricValueSelect;
	ReferencePath : OPTIONAL IfcReference;
END_ENTITY;

8.3.3.2.5 References

IfcConstraint