IfcPropertySetDefinition

BACnet MVD

#### IfcPropertySetDefinition

Natural language names

| Definition der Merkmalliste (allgemein)
| Property Set Definition
| Définition d'ensemble de propriété

##### Semantic definitions at the entity

Entity definition

IfcPropertySetDefinition is a generalization of all individual property sets that can be assigned to an object or type object. The property set definition can be either:

- Dynamically extendable property sets - IfcPropertySet, a set of properties for which the IFC specification only provides a kind of "meta model", to be further declared by agreement. This means no entity definition of the properties exists within the IFC specification. The declaration is done by assigning a significant string value to the Name attribute of the entity as defined in the entity IfcPropertySet and at each subtype of IfcProperty, referenced by the property set. Dynamically defined property sets may have an underlying template provided by IfcPropertySetTemplate.
- Statically defined property sets - IfcPreDefinedPropertySet, a property set entity that exists within the IFC specification. The semantic meaning of each statically defined property set is declared by its entity type and the meaning of the properties is defined by the name and data type of the explicit attribute representing it.

Property set definitions define information that is shared among multiple instances of objects, either object occurrences or object types. IfcPropertySetDefinition's (by their instantiable subtypes) can participate within the following relationships:

- Assignment to object types - an DefinesType direct relationship to IfcTypeObject that applies the property set, with all included properties, to the object type. Those properties apply to all object occurrences having the same object type.
- Assignment to object occurrences - an DefinesOccurrence relationship to IfcRelDefinesByProperties that applies the property set, with all included properties, to the object occurrence.

> NOTE Properties assigned to object occurrences may override properties assigned to the object type. See IfcRelDefinesByType for further information.

> HISTORY New entity in IFC2x

> IFC4 CHANGE The subtype IfcPreDefinedPropertySet has been added.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

DefinesType

IfcTypeObject
@HasPropertySets

S[0:?]

The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object.

> NOTE The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard.

> IFC4 CHANGE The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.

X

IsDefinedBy

IfcRelDefinesByTemplate
@RelatedPropertySets

S[0:?]

Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties.

> IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.

X

DefinesOccurrence

IfcRelDefinesByProperties
@RelatingPropertyDefinition

S[0:?]

Reference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties.

> IFC4 CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.

X

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId |  | Assignment of a globally unique identifier within the entire software world. | X | X

2

OwnerHistory

IfcOwnerHistory

?

Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,

> NOTE only the last modification in stored - either as addition, deletion or modification.

> IFC4 CHANGE The attribute has been changed to be OPTIONAL.

X

X

3 | Name | IfcLabel | ? | Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. | X | X
4 | Description | IfcText | ? | Optional description, provided for exchanging informative comments. |  | X
IfcPropertyDefinition
| HasContext | IfcRelDeclares @RelatedDefinitions | S[0:1] |  |  | X
| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | Reference to the relationship IfcRelAssociates and thus to those externally defined concepts, like classifications, documents, or library information, which are associated to the property definition. |  | X
IfcPropertySetDefinition

DefinesType

IfcTypeObject
@HasPropertySets

S[0:?]

The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object.

> NOTE The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard.

> IFC4 CHANGE The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.

X

IsDefinedBy

IfcRelDefinesByTemplate
@RelatedPropertySets

S[0:?]

Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties.

> IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange.

X

DefinesOccurrence

IfcRelDefinesByProperties
@RelatingPropertyDefinition

S[0:?]

Reference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties.

> IFC4 CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.

X

##### Definitions applying to Design Transfer View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View

##### Definitions applying to BACnet View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View

##### Formal representations

XML Specification
`<xs:element name="IfcPropertySetDefinition" type="ifc:IfcPropertySetDefinition" abstract="true" substitutionGroup="ifc:IfcPropertyDefinition" nillable="true"/>
<xs:complexType name="IfcPropertySetDefinition" abstract="true">
<xs:complexContent>
<xs:extension base="ifc:IfcPropertyDefinition"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcPropertySetDefinition
ABSTRACT SUPERTYPE OF(ONEOF(IfcPreDefinedPropertySet, IfcPropertySet, IfcQuantitySet))
SUBTYPE OF (IfcPropertyDefinition);
INVERSE
DefinesType : SET [0:?] OF IfcTypeObject FOR HasPropertySets;
IsDefinedBy : SET [0:?] OF IfcRelDefinesByTemplate FOR RelatedPropertySets;
DefinesOccurrence : SET [0:?] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;
END_ENTITY;

EXPRESS-G diagram

`

References: IfcRelDefinesByTemplate IfcTypeObject IfcPropertySetDefinitionSelect

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