8.3.3.3 IfcObjective

8.3.3.3.1 Semantic definition

An IfcObjective captures qualitative information for an objective-based constraint.

IfcObjective 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 IfcObjective is to specify the purpose for which the constraint is applied and to capture the benchmark metrics of the constraint.

8.3.3.3.2 Entity inheritance

8.3.3.3.3 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
IfcObjective (4)
8	BenchmarkValues	OPTIONAL LIST [1:?] OF IfcConstraint	A list of nested constraints. IFC2X4-CHANGE Modified to be a LIST of nested constraints, which replaces the former IfcConstraintAggregationRelationship.
9	LogicalAggregator	OPTIONAL IfcLogicalOperatorEnum	Enumeration that identifies the logical type of aggregation for the benchmark metrics. IFC2X4-CHANGE This attribute replaces replaces the former ResultValues attribute and indicates the aggregation behavior formerly defined at IfcConstraintAggregationRelationship.
10	ObjectiveQualifier	IfcObjectiveEnum	Enumeration that qualifies the type of objective constraint.
11	UserDefinedQualifier	OPTIONAL IfcLabel	A user defined value that qualifies the type of objective constraint when ObjectiveQualifier attribute of type IfcObjectiveEnum has value USERDEFINED.

Table 8.3.3.3.A

8.3.3.3.4 Formal propositions

Name Description

WR21

The attribute UserDefinedQualifier must be asserted when the value of the ObjectiveQualifier is set to USERDEFINED.

 (ObjectiveQualifier <> IfcObjectiveEnum.USERDEFINED) OR
((ObjectiveQualifier = IfcObjectiveEnum.USERDEFINED) AND EXISTS(SELF\IfcObjective.UserDefinedQualifier))

Table 8.3.3.3.B

8.3.3.3.5 Formal representation

 ENTITY IfcObjective
 SUBTYPE OF (IfcConstraint);
	BenchmarkValues : OPTIONAL LIST [1:?] OF IfcConstraint;
	LogicalAggregator : OPTIONAL IfcLogicalOperatorEnum;
	ObjectiveQualifier : IfcObjectiveEnum;
	UserDefinedQualifier : OPTIONAL IfcLabel;
 WHERE
	WR21 : (ObjectiveQualifier <> IfcObjectiveEnum.USERDEFINED) OR
((ObjectiveQualifier = IfcObjectiveEnum.USERDEFINED) AND EXISTS(SELF\IfcObjective.UserDefinedQualifier));
END_ENTITY;

8.3.3.3.6 References

IfcConstraint