IFC 4.3.x development

8.3.3.3 IfcObjective

Change log

IFC4

modificationsattributes BenchmarkValues definitionChanged from IfcMetric to list[1:?] of IfcConstraint
modificationsattributes ResultValues definition Changed from IfcMetric to IfcLogicalOperatorEnum
modificationsattributes ResultValues name Changed from ResultValues to LogicalAggregator

8.3.3.3.1 Semantic definitions at the entity

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.

HISTORY  New entity in IFC2.0.

IFC4 CHANGE  Attribute BenchmarkValues modified to be a LIST of IfcConstraint, attribute ResultValues replaced with IfcLogicalOperatorEnum.

8.3.3.3.1 Attributes

# Attribute Type Description
IfcConstraint
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 RelatedResourceObjectsReference to an external references, e.g. library, classification, or document information, that are associated to the constraint.

> IFC4 CHANGE New inverse attribute.
PropertiesForConstraintSET [0:?] OF IfcResourceConstraintRelationship FOR RelatingConstraint Reference to the properties to which the constraint is applied.
IfcObjective
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.

8.3.3.3.2 Entity inheritance

dot_inheritance IfcObjective IfcObjective IfcConstraint IfcConstraint IfcObjective->IfcConstraint IfcMetric IfcMetric IfcMetric->IfcConstraint

8.3.3.3.3 Formal representations

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;