8.2.3.3 IfcObjective

Objectif: Capture l'information quantitative associée à une contrainte de type objectif.
Ziel (der Einschränkung)

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.

XSD Specification:

 <xs:element name="IfcObjective" type="ifc:IfcObjective" substitutionGroup="ifc:IfcConstraint" nillable="true"/>
 <xs:complexType name="IfcObjective">
  <xs:complexContent>
   <xs:extension base="ifc:IfcConstraint">
    <xs:sequence>
     <xs:element name="BenchmarkValues" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcConstraint" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcConstraint"/>
       <xs:attribute ref="ifc:cType" fixed="list"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
    <xs:attribute name="ObjectiveQualifier" type="ifc:IfcObjectiveEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

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

Attribute Definitions:

BenchmarkValues : A list of nested constraints.
IFC2X4 CHANGE  Modified to be a LIST of nested constraints, which replaces the former IfcConstraintAggregationRelationship.
ObjectiveQualifier : Enumeration that qualifies the type of objective constraint.
UserDefinedQualifier : A user defined value that qualifies the type of objective constraint when ObjectiveQualifier attribute of type IfcObjectiveEnum has value USERDEFINED

Formal Propositions:

WR21 : The attribute UserDefinedQualifier must be asserted when the value of the ObjectiveQualifier is set to USERDEFINED.

Inheritance Graph:

ENTITY IfcObjective
ENTITY IfcConstraint
Name : IfcLabel;
Description : OPTIONAL IfcStrippedOptional;
ConstraintGrade : IfcConstraintEnum;
ConstraintSource : OPTIONAL IfcStrippedOptional;
CreatingActor : OPTIONAL IfcStrippedOptional;
CreationTime : OPTIONAL IfcStrippedOptional;
UserDefinedGrade : OPTIONAL IfcStrippedOptional;
INVERSE
ENTITY IfcObjective
BenchmarkValues : OPTIONAL LIST [1:?] OF IfcConstraint;
LogicalAggregator : OPTIONAL IfcStrippedOptional;
ObjectiveQualifier : IfcObjectiveEnum;
UserDefinedQualifier : OPTIONAL IfcStrippedOptional;
END_ENTITY;

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