#### 8.14.3.4 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 128 for an example of a bounded property:

- If the Unit attribute is not given, then the unit is already implied by the type of IfcMeasureValue or IfcDerivedMeasureValue. The associated unit can be found at the IfcUnitAssignment globally defined at the project level (IfcProject.UnitsInContext).
- If the Unit attribute is given, then the unit assigned by the Unit attribute overrides the globally assigned unit.

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 128 — 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:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcPropertyBoundedValue

| SUBTYPE OF (IfcSimpleProperty);

UpperBoundValue | : | OPTIONAL IfcStrippedOptional;
LowerBoundValue | : | OPTIONAL IfcStrippedOptional;
Unit | : | OPTIONAL IfcStrippedOptional;
SetPointValue | : | OPTIONAL IfcStrippedOptional;

| 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;

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

| ENTITY IfcProperty

Name | : | IfcIdentifier;
Description | : | OPTIONAL IfcStrippedOptional;

| INVERSE

PartOfPset | : | SET OF IfcPropertySet FOR HasProperties;

| ENTITY IfcSimpleProperty

| ENTITY IfcPropertyBoundedValue

UpperBoundValue | : | OPTIONAL IfcStrippedOptional;
LowerBoundValue | : | OPTIONAL IfcStrippedOptional;
Unit | : | OPTIONAL IfcStrippedOptional;
SetPointValue | : | OPTIONAL IfcStrippedOptional;

END_ENTITY;

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