|Teil zu Ganzes Beziehung geordnet - Relation|
The nesting relationship IfcRelNests is a special type
of the general composition/decomposition (or whole/part)
relationship IfcRelDecomposes. The nesting
relationship can be applied to all non physical subtypes of
object and object types, namely processes, controls (like
cost items), and resources. It can also be applied to
physical subtypes of object and object types, namely elements
having ports. The nesting implies an order among the nested
EXAMPLE A nesting of costs items in an
IfcCostSchedule is the composition of complex cost
items from other cost items. The order of the nested cost
items underneath the parent cost item is determined by the
order of the list of RelatedObjects.
EXAMPLE A nesting of IfcTask's within a work
schedule is the composition of a parent work task from more
specific sub work tasks. The order of the sub tasks
underneath the parent task is determined by the order of the
list of RelatedObjects.
EXAMPLE A series of IfcDistributionPort's can
be nested within an IfcDistributionElement. They
decompose the distribution element and have an implied order.
Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts
depend on the existence of the whole. The behaviour that is
implied from the dependency has to be established inside the
HISTORY New entity in IFC2.0
IFC4 CHANGE The attributes RelatingObject and
RelatedObjects are demoted from the supertype
IfcRelDecomposes, and RelatedObjects is refined
to be a list. The use of IfcRelNests is repurposed to
be a nesting of an ordered collections of parts.
XSD Specification: <xs:element name="IfcRelNests" type="ifc:IfcRelNests" substitutionGroup="ifc:IfcRelDecomposes" nillable="true"/>
<xs:element name="RelatingObject" type="ifc:IfcObjectDefinition" nillable="true"/>
<xs:element ref="ifc:IfcObjectDefinition" maxOccurs="unbounded"/>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcObjectDefinition"/>
<xs:attribute ref="ifc:cType" fixed="list"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
|NoSelfReference|| : ||SIZEOF(QUERY(Temp <* RelatedObjects | RelatingObject :=: Temp)) = 0;|
|RelatingObject|| : ||
The object definition, either an non-product object type or a non-product object occurrence, that represents the nest. It is the whole within the whole/part relationship.
IFC4 CHANGE The attribute has been demoted from the supertype IfcRelDecomposes and defines the ordered nesting relationship.
|RelatedObjects|| : ||
The object definitions, either non-product object occurrences or non-product object types, that are being nestes. They are defined as the parts in the ordered whole/part relationship - i.e. there is an implied order among the parts expressed by the position within the list of RelatedObjects.
IFC4 CHANGE The attribute has been demoted from the supertype IfcRelDecomposes and defines the ordered set of parts within the nest.
|NoSelfReference|| : ||
The instance to with the relation points as provided by RelatingObject shall not be contained in the list of RelatedObjects.
Link to this page