8.16.3.6 IfcPropertyBoundedValue

Propriété à valeur bornée
Merkmal mit Grenzwerten

A property with a bounded value, IfcPropertyBoundedValue, defines a property object which has a maximum of two (numeric or descriptive) values assigned, the first value specifying the upper bound and the second value specifying the lower bound. It defines a property - value bound (min-max) combination for which the property Name, an optional Description, the optional UpperBoundValue with measure type, the optional LowerBoundValue with measure type, and the optional Unit is given. A set point value can be provided in addition to the upper and lower bound values for operational value setting.

The unit is handled by the Unit attribute, see Table 687 for an example of a bounded property:

The IfcPropertyBoundedValue allows for the specification of an interval for the value component of the property description. If either the LowerBoundValue or the UpperBoundValue is not given, then it indicates an open bound (either a minimum value or a maximum value). The interval is by definition inclusive, that is, the value given for the LowerBoundValue or the UpperBoundValue is included in the interval.

NOTE  An IfcPropertyBoundedValue may be exchanged with no values assigned yet. In this case the LowerBoundValue and the UpperBoundValue are set to NIL.

 

Name UpperBoundValue LowerBoundValue SetPointValue Type
(through IfcValue)
Unit
OverallHeight 1930 2300 <nil> IfcPositiveLengthMeasure -
OverallWidth 0.9 1.25 <nil> IfcPositiveLengthMeasure m
MaxHeight 20.0 <nil> <nil> IfcPositiveLengthMeasure -
MinWeight <nil> 20 <nil> IfcMassMeasure kg
* Where rules ensures same measure type for all values

Table 687 — Bounded property with values, measure types and units

HISTORY  New entity in IFC2x.
IFC2x2 CHANGE  The attribute type of the attribute UpperBoundValue and LowerBoundValue has been made optional with upward compatibility for file based exchange.
IFC4 CHANGE  The attribute SetPointValue has been added.

Informal Propositions:

  1. If the measure type for the upper and lover bound value is a numeric measure, then the following shall be true: UpperBoundValue > LowerBoundValue.

XSD Specification:

 <xs:element name="IfcPropertyBoundedValue" type="ifc:IfcPropertyBoundedValue" substitutionGroup="ifc:IfcSimpleProperty" nillable="true"/>
 <xs:complexType name="IfcPropertyBoundedValue">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSimpleProperty">
    <xs:sequence>
     <xs:element name="UpperBoundValue" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcValue"/>
      </xs:complexType>
     </xs:element>
     <xs:element name="LowerBoundValue" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcValue"/>
      </xs:complexType>
     </xs:element>
     <xs:element name="Unit" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcUnit"/>
      </xs:complexType>
     </xs:element>
     <xs:element name="SetPointValue" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcValue"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcPropertyBoundedValue
SUBTYPE OF IfcSimpleProperty;
UpperBoundValue : OPTIONAL IfcValue;
LowerBoundValue : OPTIONAL IfcValue;
Unit : OPTIONAL IfcUnit;
SetPointValue : OPTIONAL IfcValue;
WHERE
SameUnitUpperLower : NOT(EXISTS(UpperBoundValue)) OR NOT(EXISTS(LowerBoundValue)) OR (TYPEOF(UpperBoundValue) = TYPEOF(LowerBoundValue));
SameUnitUpperSet : NOT(EXISTS(UpperBoundValue)) OR NOT(EXISTS(SetPointValue)) OR (TYPEOF(UpperBoundValue) = TYPEOF(SetPointValue));
SameUnitLowerSet : NOT(EXISTS(LowerBoundValue)) OR NOT(EXISTS(SetPointValue)) OR (TYPEOF(LowerBoundValue) = TYPEOF(SetPointValue));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

UpperBoundValue : Upper bound value for the interval defining the property value. If the value is not given, it indicates an open bound (all values to be greater than or equal to LowerBoundValue).
LowerBoundValue : Lower bound value for the interval defining the property value. If the value is not given, it indicates an open bound (all values to be lower than or equal to UpperBoundValue).
Unit : Unit for the upper and lower bound values, if not given, the default value for the measure type is used as defined by the global unit assignment at IfcProject.UnitInContext. The applicable unit is then selected by the underlying TYPE of the UpperBoundValue, LowerBoundValue, and SetPointValue)
SetPointValue : Set point value as typically used for operational value setting.
IFC4 CHANGE  The attribute has been added at the end of the attribute list.

Formal Propositions:

SameUnitUpperLower : The measure type of the UpperBoundValue shall be the same as the measure type of the LowerBoundValue, if both (upper and lower bound) are given.
SameUnitUpperSet : The measure type of the UpperBoundValue shall be the same as the measure type of the SetPointValue, if both (upper bound and set point) are given.
SameUnitLowerSet : The measure type of the LowerBoundValue shall be the same as the measure type of the SetPointValue, if both (lower bound and set point) are given.

Inheritance Graph:

ENTITY IfcPropertyBoundedValue
ENTITY IfcPropertyAbstraction
INVERSE
HasExternalReferences : SET OF IfcExternalReferenceRelationship FOR RelatedResourceObjects;
ENTITY IfcProperty
Name : IfcIdentifier;
Description : OPTIONAL IfcText;
INVERSE
PartOfPset : SET OF IfcPropertySet FOR HasProperties;
PropertyForDependance : SET OF IfcPropertyDependencyRelationship FOR DependingProperty;
PropertyDependsOn : SET OF IfcPropertyDependencyRelationship FOR DependantProperty;
PartOfComplex : SET OF IfcComplexProperty FOR HasProperties;
ENTITY IfcSimpleProperty
ENTITY IfcPropertyBoundedValue
UpperBoundValue : OPTIONAL IfcValue;
LowerBoundValue : OPTIONAL IfcValue;
Unit : OPTIONAL IfcUnit;
SetPointValue : OPTIONAL IfcValue;
END_ENTITY;

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