IfcSystem

Natural language names
deSystem (allgemein)
enSystem
frSystème
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcSystem
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
Semantic definitions at the entity
Entity definition

A system is an organized combination of related parts within an AEC product, composed for a common purpose or function or to provide a service. A system is essentially a functionally related aggregation of products. The grouping relationship to one or several instances of IfcProduct (the system members) is handled by IfcRelAssignsToGroup.

NOTE  The use of IfcSystem often applies to the representation of building services related systems, such as the piping system, cold water system, etc. Members within such a system may or may not be connected using the connectivity related entities (through IfcDistributionPort).
HISTORY  New entity in IFC1.0
Attribute definitions
#AttributeTypeCardinalityDescription C
ServicesBuildingsIfcRelServicesBuildings
@RelatingSystem		S[0:1]Reference to the building spatial structure via the objectified relationship IfcRelServicesBuildings, which is serviced by the system. X
Inherited definitions from supertypes
Entity inheritance IfcBuildingSystem IfcDistributionSystem IfcStructuralAnalysisModel IfcZone IfcGroup IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[0:1] 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.
X
3NameIfcLabel[0:1] 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
4DescriptionIfcText[0:1] Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects		S[0:?]Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.X
NestsIfcRelNests
@RelatedObjects		S[0:1]References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only). X
IsNestedByIfcRelNests
@RelatingObject		S[0:?]References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types). X
HasContextIfcRelDeclares
@RelatedDefinitions		S[0:1]References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object. X
IsDecomposedByIfcRelAggregates
@RelatingObject		S[0:?]References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts). X
DecomposesIfcRelAggregates
@RelatedObjects		S[0:1]References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only). X
HasAssociationsIfcRelAssociates
@RelatedObjects		S[0:?]Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.X
IfcObject
5ObjectTypeIfcLabel[0:1] The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
X
IsDeclaredByIfcRelDefinesByObject
@RelatedObjects		S[0:1]Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. X
DeclaresIfcRelDefinesByObject
@RelatingObject		S[0:?]Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. X
IsTypedByIfcRelDefinesByType
@RelatedObjects		S[0:1]Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type. X
IsDefinedByIfcRelDefinesByProperties
@RelatedObjects		S[0:?]Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object. X
IfcGroup
IsGroupedByIfcRelAssignsToGroup
@RelatingGroup		S[0:?]Reference to the relationship IfcRelAssignsToGroup that assigns the one to many group members to the IfcGroup object. X
IfcSystem
ServicesBuildingsIfcRelServicesBuildings
@RelatingSystem		S[0:1]Reference to the building spatial structure via the objectified relationship IfcRelServicesBuildings, which is serviced by the system. X
Definitions applying to Common Use Definitions

 Instance diagram

Concept usage

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 75.

PredefinedTypeNameProperties
 Pset_ServiceLifeFactorsBounded Value
NameValueValue
QualityOfComponentsIfcPositiveRatioMeasureIfcPositiveRatioMeasure
DesignLevelIfcPositiveRatioMeasureIfcPositiveRatioMeasure
WorkExecutionLevelIfcPositiveRatioMeasureIfcPositiveRatioMeasure
IndoorEnvironmentIfcPositiveRatioMeasureIfcPositiveRatioMeasure
OutdoorEnvironmentIfcPositiveRatioMeasureIfcPositiveRatioMeasure
InUseConditionsIfcPositiveRatioMeasureIfcPositiveRatioMeasure
MaintenanceLevelIfcPositiveRatioMeasureIfcPositiveRatioMeasure

Table 75 — IfcSystem Property Sets for Objects



Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityCommon Use Definitions
Revision ControlCommon Use Definitions
IfcObject
Object Occurrence Predefined TypeCommon Use Definitions
IfcGroup
Group AssignmentCommon Use Definitions
IfcSystem
Property Sets for ObjectsCommon Use Definitions
Formal representations
XSD Specification
 <xs:element name="IfcSystem" type="ifc:IfcSystem" substitutionGroup="ifc:IfcGroup" nillable="true"/>
 <xs:complexType name="IfcSystem">
  <xs:complexContent>
   <xs:extension base="ifc:IfcGroup"/>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcSystem
 SUPERTYPE OF(ONEOF(IfcBuildingSystem, IfcDistributionSystem, IfcStructuralAnalysisModel, IfcZone))
 SUBTYPE OF (IfcGroup);
 INVERSE
  ServicesBuildings : SET [0:1] OF IfcRelServicesBuildings FOR RelatingSystem;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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