EXPRESS Definition
EXPRESS-G Diagram
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EXPRESS Definition |
EXPRESS-G Diagram |
No Simple Types defined in this Schema
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
O IfcObjectWithPlacementSelect
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
C IfcContainedOrReferencedEnum
IfcContainmentEnumP IfcProxyEnum R IfcResourceConsumptionEnum S IfcSequenceEnum
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
No Functions defined in this Schema
The schema IfcKernel defines the most abstract part within the IFC architecture. It captures general constructs, that are basically founded by their different semantic meaning in common understanding of an object model, like object, property and relationship. Those are then specialized into non-AEC/FM specific constructs, like product, process, control and resource, which form the main entry points for the next level, the Core Extension layer.
The IfcKernel utilizes the translation of the IFC Meta model into IFC object model specification. It handles the basic functionality, such as relative location of products in space, sequence of processes in time, or general purpose grouping and nesting mechanism. It also lays the foundation of extensibility of IFC model by providing type driven property definition and property definition extension.
The specification of IfcKernel is not intended for independent implementation, however, all shared and domain models at lower levels within the IFC architecture are required to use the kernel definitions to root their definitions.
HISTORY This schema is new in IFC Release 1.5
EXPRESS Definition
Definition from IAI: The IfcObjectWithPlacementSelect defines the three high level classes in IFC, that define their own placement. These objects can therefore provide the local (or in case of IfcProject -- global) coordinate system to which other object coordinate systems can refer.
This Select Type has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-212 and I-312 for changes made in IFC Release 1.5.
EXPRESS Definition
Definition from IAI: This enumeration defines the whether the containment type is "Contained" or "Referenced". Contained means a hierarchical relationship between the contained item and the container, where any item can only be contained once. Referenced means a non-hierarchical relationship between the referenced item and the referencing container, where any item can be referenced by one or many referencing containers.
The term "container" is used for any item in a logical structuring systems, to which an object is assigned to (either "Contained" or "Referenced"). A structuring system can be the project structure of site à building à building story à space, where each individual site, building, building story, or space object can act as an "container" for objects.
EXAMPLE A multi-story space is contained (i.e. in hierarchic relationship) to the building story, on which its ground level is. The same multi-story space is referenced by any building story, through which it spans.
New Enumeration in IFC Release 2.0
ISSUE See Issues I-114 and I-116 for changes made in IFC Release 1.5.
Contained
Referenced
EXPRESS Definition
Definition from IAI: This enumeration defines the different containment types, that further refine the containment relationship.
This Enumeration has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See Issues I-114 and I-116 for changes made in IFC Release 1.5.
ProjectContainer
SiteContainer
BuildingContainer
BuildingStoreyContainer
SpaceContainer
ZoneContainer
NotDefined
EXPRESS Definition
Definition from IAI: This enumeration defines the high level categorization of an IfcProxy. It indicates to which subtype of IfcObject the Proxy would otherwise comply.
This Enumeration has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-184 for changes made in IFC Release 1.5.
Product
Process
Control
Document
Resource
NotDefined
EXPRESS Definition
Definition from IAI: This enumeration indicates how the resource is consumed during the use.
New Enumeration in IFC Release 2.0
ISSUE See issue I-487 for changes made in IFC Release 2.0.
Consumed
PartiallyConsumed
Occupied
PartiallyOccupied
NotOccupied
UserDefined
NotDefined
EXPRESS Definition
Definition from IAI: : This enumeration defines the different ways, in which a time lag is applied to a sequence between two processes.
This Enumeration has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-200 for changes made in IFC Release 1.5.
Start_Start
Start_Finish
Finish_Start
Finish_Finish
NotDefined
 Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The IfcActor defines all actors or human agents involved in a project during its full life cycle. It facilitates the use of person and organization definitions in the resource part of the IFC object model.
New Class in IFC Release 2.0
ISSUE See issues I-478, I-516 for changes made in IFC Release 2.0.
IfcRoot
IfcObject
IfcOccupant
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
TheActor
Information about the actor
INV
IsActingUpon
SET [0:?] OF IfcRelActsUpon
Reference to the relationship that associates the actor to an object.
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EXPRESS Definition |
Definition from IAI: The IfcControl is the abstract generalization of all concepts that control or constrain Products or Processes in general. It can be seen as a specification, regulation, constraint or other requirement applied to a product or process whose requirements and provisions must be fulfilled.
Examples for Controls are space program, construction guides, etc. It is defined in the Kernel but will be reused and specialized in other schemas.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-094 for changes made in IFC Release 1.5.
IfcRoot
IfcConnectionGeometry
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
Classification
Reference to the access information for classified information. NOTE: not the classified information is referenced, only the unambiguous access to it.
INV
Controls
SET [0:?] OF IfcRelControls
Reference to the relationship that associates the control to the object(s) being controled.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: Defines those dynamically extendable properties that are defined as extensions to the IFC Object model (see semantic definition of IfcObject). Extension property sets can form part of a regional flavor of IFC or can be project specific extensions to the actual content of an IFC release. The definition source (the body that defined the extension) has to be given.
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
DefinitionSource
STRING
The Source attribute specifies the source of the external definition. It can be either the name of a recognised country or region, which defines a national flavour of IFC, or the name of a project consortium, or the name of a group of implementers.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The generalization of any arbitrary group. A group is an aggregation of objects, which do not have any particular positioning relationship. Therefore a group is an aggregation under some non-geometrical/topological grouping aspects. An example for a group is the system, since it groups elements under the aspect of their role, regardless of their position in a building. A group can hold an aggregation of products, processes or other groups. Groups can therefore be nested.
The GroupPurpose attribute may assign a descriptor, that defines the purpose of the group. As an example, a complex of buildings will be generated by assigning the individual buildings through the IfcRelGroups relationship to an IfcGroup, which is further specified by the GroupPurpose descriptor "BuildingComplex". Similarly the site complex is handled by an IfcGroup with the GroupPurpose descriptor "SiteComplex".
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-088 and I-213 for changes made in IFC Release 1.5.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
GroupPurpose
STRING
Description of the Purpose behind grouping.
INV
IsGroupedBy
Contains the relationship that assigns the group members to the group object.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The relative placement between two products. It defines that the related object is placed within the local coordinate system of the relating object. Rules to prevent cyclic relative placements have to be introduced on the application level.
The following conventions shall apply, if relative placement is used:
- IfcSite shall be placed relative to IfcProject (i.e. WCS)
- IfcBuilding shall be placed relative to IfcSite
- IfcBuildingStorey shall be placed relative to IfcBuilding
- IfcElement shall be placed relative:
- to its container (IfcSite, IfcBuilding, IfcBuildingStorey), or
- to the IfcElement to which it is tied by an element relationship (IfcRelVoidsElement, IfcRelFillsElement, IfcRelCoversBldgElements, IfcRelAssemblesElements), or
- to the modeling aid (Grid)
If the PlacementRelTo Relationship is not given, then it defaults to an absolute placement within the WCS, i.e. relative to the IfcProject.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-212, I-255, I-260 and I-270 for changes made in IFC Release 1.5.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
PlacementRelTo
Reference to Object that provides the relative placement by its local coordinate system, if it is omitted, then the Local Placement is given to the WCS, established by the IfcProject.
RelativePlacement
Geometric placement that defines the transformation from the related coordinate system into the relating. The placement can be either 2D or 3D, depending on the dimension count of the coordinate system.
WR31
Either PlacementRelTo is not given, or it shall not refer to an IfcLocalPlacement directly.
(NOT(EXISTS(PlacementRelTo))) OR (NOT('IFCKERNEL.IFCLOCALPLACEMENT' IN TYPEOF(PlacementRelTo)))
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EXPRESS Definition |
Definition from IAI: An IfcModelingAid provides the general concept for constructs that support the creation of design artifact, in particular its geometric form. They are part of the project information set, but not part of the artifact itself. Most common example of a modeling aid are the local placement and the design grid. Both provide aid to place Products into the design space. The grid supports in addition the definition of elements' constraint location and sometimes form, but the grid is not part of the constructed building.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-254 and I-255 for changes made in IFC Release 1.5.
IfcRoot
No attributes defined on this level.
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EXPRESS Definition |
Definition from IAI: The generalization of any semantically treated things and processes within IFC. Examples of IfcObject include physically tangible items, such as wall, beam or covering, physically existing items, such as spaces, or conceptual items, such as grids or virtual boundaries. It also stands for processes, such as work tasks, as well as for controls, etc.
Objects are independent pieces of information that might contain or reference other pieces of information, most notably properties. Properties of objects can be of either of the following types:
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
UserDefinedType
STRING
User defined type, given for the instantiable subtypes of IfcObject. If for a given subtype, a predefined type exists (an attribute PredefinedType with the data type Enumaration, then the value for user defined is only valid, if the predefined value is set to UserDefined. Allows for the addition of regional extensions of IFC.
DocumentReferences
SET [0:?] OF IfcDocumentReference
Reference to a document reference that holds the access information to an externally provided document.
INV
PartOfGroups
SET [0:?] OF IfcRelGroups
References to the grouping relationships, which allows the object to be part of many groups
INV
Nests
SET [0:1] OF IfcRelNests
Reference to the nesting relationship, that allows this object to be the nest of other nested objects
INV
IsNestedBy
SET [0:?] OF IfcRelNests
References to the nesting relationship, that allows this object to be nested within other objects
INV
Contains
SET [0:2] OF IfcRelContains
Set of Relationships to other Objects that are contained by this object.
INV
IsContainedBy
SET [0:?] OF IfcRelContains
Set of Relationships to other Objects in which this object is contained.
INV
OperatedInProcesses
SET [0:?] OF IfcRelProcessOperatesOn
Set of Relationships to processes which operated on the object.
INV
IsDefinedBy
SET [0:?] OF IfcRelAssignsProperties
Set of Relationships to properties (statically or dynamically defined) that further define the object..
INV
IsActedUpon
SET [0:?] OF IfcRelActsUpon
Set of Relationships to actors which acts upon the object.
INV
IsControlledBy
SET [0:?] OF IfcRelControls
Set of Relationships to controls which apply a control to the object.
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EXPRESS Definition |
Definition from IAI: An action taking place in building construction with the intent of acquiring or constructing products. Processes are placed in sequence (including overlapping for parallel tasks) in time.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-200, I-201 for changes made in IFC Release 1.5.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
Productivity
Productivity of the process (such as m³ per hour)
OPT
Classification
Reference to the access information for classified information. NOTE: not the classified information is referenced, only the unambiguous access to it.
INV
IsSuccessorFrom
SET [0:?] OF IfcRelSequence
Relative placement in time, refers to the previous processes for which this process is successor.
INV
IsPredecessorTo
SET [0:?] OF IfcRelSequence
Relative placement in time, refers to the previous processes for which this process is predecessor.
INV
OperatesOn
SET [0:?] OF IfcRelProcessOperatesOn
Set of Relationships to objects that are operated on by the process
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EXPRESS Definition |
Definition from IAI: Any object, manufactured, supplied or created for incorporation into an AEC/FM project. This also includes objects that are created indirectly by other products, as spaces are defined by bounding elements. Products can be designated for permanent use or temporary use, an example for the latter is formwork.
Products are defined by their properties and representations. Products occur at a specific location in space. They can be placed relatively to other products, but ultimately relative to the world coordinate system defined for this project.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
LocalPlacement
Contained relative placement in space, refers to the product that provides the local coordinate system for the Relative Placement and includes the transformation for the object coordinate system.
Representations
SET [0:2] OF IfcProductRepresentation
Reference to the representations of the product, being either geometric shape representations or topological representations, or both. The product definition shape provides for multiple representations of the shape property of the object. The product definition topology provides for basic topology and connectivity information.
OPT
Classification
Reference to the access information for classified information. NOTE: not the classified information is referenced, only the unambiguous access to it.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The undertaking of some engineering activities leading towards a product. It acts as the top container for all objects defining a project. The Project also holds the units used for certain measures throughout the project and the central registry, currently only for team members, applications and materials. The IfcProject establishes the World Coordinate System, WCS.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-084, I-001, I-003 for changes made in IFC Release 1.5.
See issues I-298, I-328 for changes made in IFC Release 1.5.1.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
OPT
ReferenceName
STRING
Short name for the project as used for reference purposes.
OPT
Name
STRING
Long name for the project.
OPT
Phase
STRING
Current project phase, open to interpretation for all project partner, therefore given as IfcString.
UnitsInContext
Defines the units of measure that will be referred by defined data types in the attribute values of all attributes and properties of objects and relationships, defined in the context of this project.
OPT
Classification
Reference to the access information for classified information. NOTE: not the classified information is referenced, only the unambiguous access to it.
AbsolutePlacement
Establishment of the World Coordinate System for the Project
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EXPRESS Definition |
Definition from IAI: Defines the generalization of all properties (dynamically defined and statically defined). It cannot be instantiated as it is an ABSTRACT class.
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
INV
DefinitionOf
Reference to the relation to one or many objects that are characterized by the property definition.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: Defines all dynamically extendable properties (see semantic definition of IfcObject). The IfcPropertySet is a container class that allows the definition of collections of IfcProperty, and the nesting of other IfcPropertySet.
New Class in IFC Release 2.0
ISSUES: See issues I-078, I-080, I-187, GI-003 for changes made in IFC Release 1.5.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
Name
STRING
Name of the property set as used within the project. The attribute is used to dynamically specify the type of the property definition. Directly instantiated at IfcPropertySet it provides for the properties defined as part of the IFC Object model (see semantic definition at IfcObject). The property set structure for that IfcPropertySet is given within the property set definition part of the IFC specification.
HasProperties
LIST [1:?] OF IfcProperty
Contained list of properties. For property sets defined as part of the IFC Object model, the property objects within a property set are defined as part of the standard. If a property is not contained within the list of predefined properties, ist value has not been set at this time.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The IfcProxy is intended to be a kind of a container for wrapping up non-IFC objects for use within the persistent store. Given that we have only a limited number of constructs formally defined within IFC (and will never be able to define them all), we must provide a mechanism for capturing constructs (primarily geometric) that are not defined by IFC. These constructs may or may not have semantic meaning, depending on whether any representations or extended property sets are attached to the IfcProxy. Either way, a receiving system only has to ensure that they are maintained as part of the project model. Such a mechanism allows to exchange data that is part of the project but not necessarily part of the IFC model.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-184 for changes made in IFC Release 1.5.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
ProxyType
High level (and only) semantic meaning attached to the IfcProxy, defining the basic construct type behind the Proxy, e.g. Product or Process.
OPT
LocalPlacement
In case of a Product Proxy, the placement within the space of the Project is given.
Representations
SET [0:2] OF IfcProductRepresentation
In case of a Product Proxy, reference to the representations of the product, being either geometric shape representations or topological representations, or both. The product definition shape provides for multiple representations of the shape property of the object. The product definition topology provides for basic topology and connectivity information.
WR2
Either the proxy is a product, or it should not have geometric or topologic representations.
(ProxyType = Product) XOR ((ProxyType <> Product) AND (SIZEOF(Representations)=0))
WR33
If the IfcProxy is a Product, then a local placement shall be given, otherwise no local placement shall be given.
((ProxyType = Product) AND (EXISTS(LocalPlacement))) XOR ((ProxyType <> Product) AND NOT(EXISTS(LocalPlacement)))
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The IfcRelActsUpon objectified relationship defines a relationship between an actor and one or many objects. An particular role of the actor played in that relationship can be associated.
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingActor
Reference to the actor.
RelatedObjects
LIST [1:?] OF IfcObject
Reference to the objects (or single object) on which the actor acts upon in a certain role (if given)
OPT
ActingRole
Role of the actor played within the assignment to the object(s).
WR32
The relationship shall not define an actor to actor relationship.
SIZEOF(QUERY(Temp <* RelatedObjects | 'IFCKERNEL.IFCACTOR' IN TYPEOF(Temp))) = 0
IP31
The relationship shall be defined acyclic.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The IfcRelAssignsProperties class defines the light-weight relationships between properties and objects. Directly instantiated it provides for non-type driven property assignments (see semantic definition of IfcObject).
The IfcRelAssignsProperties is a N:M relationship, as it allows for the assignment of one to many (related) properties to a single or many objects.
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingPropertyDefinition
Reference to the property definition for that object or list of objects.
RelatedObjects
LIST [1:?] OF IfcObject
Reference to the objects (or single object) to which the property definition applies.
OPT
DomainView
STRING
The attribute DomainView optionally defines the domain, to which the assigned IfcPropertyDefinition relates. If not present, the IfcPropertyDefinition is applicable to all domain views. The DomainView is given as STRING type to allow an easy upgrade for new releases and for assigning arbitrary domain view names for externally defined property sets.
DER
IsShared
LOGICAL
The attribute IsShared reflects whether the property is assigned to a single object instance (FALSE = occurrence property,) or assigned to multiple object instances (TRUE = shared property, see semantic definition at IfcObject).
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The IfcRelAssignsTypedProperties class defines the light-weight relationships between properties and objects for type-driven property assignments (see semantic definition of IfcObject). It is provided as specialization of IfcRelAssignsProperties.
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
Name
STRING
The attributes Name defines the Name of the 'type' being defined, as given by the IFC specification. A 'type' is used to establish a standard of object property definitions, that may be used many times in a project. A given 'type' drives the assignment of one IfcPropertyDefinition instance (which might include other IfcPropertyDefinitions in case of nested property sets) to an IfcObject instance (occurrence type) or to many IfcObject instances (shared type).
OPT
TypedClass
STRING
The attribute TypedClass optionally defines the IfcObject, to which the assigned IfcPropertyDefinition relates. If not present, no instruction is given to which IfcObject the IfcPropertyDefinition is applicable.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: This objectified relationship handles the general concept of containment, that can be either realized by reference or by value. Currently the concept of containment is used for buildings as a special kind of AEC/FM products.
A distinctions is made between the containment and the reference of Elements. A containment relationship shall lead to a hierarchical relationship, i.e. each element can only be contained by one instance of a element container (i.e. site, building, building storey, zone or space). It might however be referenced by many element containers. A multi-storey space is contained (or belongs to) the building storey at which its ground level is, but it is referenced by all the other building storeys, in which it spans. A lift shaft might be contained by the basement, but referenced by all storeys, through which it spans.
A reference relationship provides for non-hierarchical relationships.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues GI-008, I-116 for changes made in IFC Release 1.5.
See issue I-310 for changes made in IFC Release 1.5.1.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingObject
Reference to the container object
RelatedObjects
LIST [1:?] OF IfcObject
Reference to the contained objects
RelationshipType
Defines the type of relationship from the relating side, i.e. following the container object, in which the other objects are contained.
ContainedOrReferenced
Defines whether the relationship is a hierarchical containment relationship (Contained) or a reference relationship (Referenced)
WR31
The instance to which the RelatingObject relation points (container) shall not be contained in the List of RelatedObjects.
SIZEOF(QUERY(Temp <* RelatedObjects | RelatingObject :=: Temp)) = 0
IP31
The IfcRelContains relationship shall be defined acyclic.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: This objectified relationship handles the assignment of controls (subtypes of IfcControl) to other objects (subtypes of IfcObject, with the exception of controls).
New Class in IFC Release 2.0
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingControl
Reference to the control that applies an control about objects.
RelatedObjects
LIST [1:?] OF IfcObject
Reference to the objects being controled.
WR31
Control shall not be applied to control objects.
SIZEOF (QUERY (temp <* RelatedObjects | 'IFCKERNEL.IFCCONTROL' IN TYPEOF(temp))) = 0
IP31
The IfcRelControls relationship shall be defined acyclic.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: This objectified relationship handles the assignment of group members to group objects. It allows for grouping arbitrary objects within a group, including other groups. The grouping relationship can be applied in a recursive manner. The resulting group is of type IfcGroup.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-310 for changes made in IFC Release 1.5.1.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingGroup
Reference to group that finally contains all assigned group members.
RelatedObjects
LIST [1:?] OF IfcObject
References to Objects that will be contained in the group.
WR31
The instance to with the relation points shall not be contained in the List of RelatedObjects.
SIZEOF(QUERY(Temp <* RelatedObjects | RelatingGroup :=: Temp)) = 0
WR32
The dependency flags shall be set so that the RelatedObjects always depend on the RelatingObject (the group)
(SELF\IfcRelationship.RelatedIsDependent = TRUE) AND (SELF\IfcRelationship.RelatingIsDependent = FALSE)
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: The nesting relationship defines the general concept of elements being nested, so that the nest is of the same type (or supertype) as the nested elements. An example is, that a cost element is a nest of other cost elements. The nesting relationship can be applied in a recursive manner.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-310 for changes made in IFC Release 1.5.1.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingObject
The object that represents the nest.
RelatedObjects
LIST [1:?] OF IfcObject
The objects being nested.
OPT
NestingPurpose
STRING
Any description to explain the criteria about nesting those objects
WR31
The instance to which the relation RelatingObject points shall not be contained in the List of RelatedObjects.
SIZEOF(QUERY(Temp <* RelatedObjects | RelatingObject :=: Temp)) = 0
WR32
The type of the RelatingObject shall always be included in the type of each RelatedObject, i.e. the RelatingObject is of the same type of a common supertype
SIZEOF(QUERY(Temp <* RelatedObjects | NOT(TYPEOF(RelatingObject) <= TYPEOF(Temp)))) = 0
WR33
The dependency flags shall be set so that the RelatedObjects always depends on the RelatingObject (the nest)
(SELF\IfcRelationship.RelatedIsDependent = TRUE) AND (SELF\IfcRelationship.RelatingIsDependent = FALSE)
WR34
Products shall not be nested (use aggregation relationships).
NOT('IFCKERNEL.IFCPRODUCT'IN TYPEOF(RelatingObject))
IP31
The IfcRelNests relationship shall be defined acyclic.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: This objectified relationship handles the assignment of an object as an item the process operates on. Process are related to the products that they operate on (input or output) through this relationship. Processes can operate on things other than products, and can operate in ways other than input and output. For example, it many be common defined processes during estimating or scheduling that describe design tasks (resulting in documents), procurement tasks (resulting in construction materials), planning tasks (resulting in processes), etc. Furthermore, the ways in which process can operate on something might include "installs", "finishes", "transports", "removes", etc. The ways are described as operation types.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issue I-310 for changes made in IFC Release 1.5.1.
See issues I-480, I-482 for changes made in IFC Release 2.0.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingProcess
Reference to Process, that handles the Products as input or output.
RelatedObject
References to an object, which the process operates on.
OperationType
STRING
Opertation type, defining the kind of operation on the object.
OperationQuantity
Quantitiy of the object specific for the operation by this process.
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Fully Attributed View |
EXPRESS Definition |
Definition from IAI: This objectified relationship handles the concatenation of processes over time. The Sequence is defined as relationship between two processes. The related object is the successor of the relating object, being the predecessor. A time lag is assigned to a sequence, and the sequence type defines the way in which the time lag applies to the sequence.
IfcRelSequence is defined as an one-to-one relationship, therefore it assigns one predecessor to one successor. However, each IfcProcess can have multiple predecessors and successors, the sequence relationship is truly N-to-M. Many instances of IfcRelSequence have to be created in order to cope with that.
This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
ISSUE See issues I-093, I-200 for changes made in IFC Release 1.5.
See issue I-310 for changes made in IFC Release 1.5.1.
IfcRoot
Attribute type (OPT, DER, INV)
Redefinition (SELF)
Attribute / Relation
Data or Rel. type
Definition
RelatingProcess
Reference to the Process, that is the predecessor.
RelatedProcess
Reference to the Process, that is the successor.
