5.3.3.7 IfcTaskType

RV ⓘ

AbV ⓘ

5.3.3.7.1 Semantic definition

An IfcTaskType defines a particular type of task that may be specified for use within a work control.

An IfcTaskType provides for all forms of types of task that may be specified. It is a reference definition for a unit of work that may be broken down into (a sequence of) subtasks. Please note that a reference definition can not be part of a workflow definition, i.e. IfcTaskType instances define the most abstract level of a reference process without dependencies to other reference processes.

Usage of IfcTaskType defines the parameters for one or more occurrences of IfcTask. Parameters may be specified through property sets that may be enumerated in the IfcTaskTypeEnum data type or through explicit attributes of IfcTaskType. Task occurrences (IfcTask entities) are linked to the task type through the IfcRelDefinesByType relationship.

Figure 5.3.3.7.A shows the definition of a task type that is part of a task template library. Please note that in this example the task type is further subdivided into tasks that define task times (for example, duration) and/or a task sequence.

task type instantiation diagram — Figure 5.3.3.7.A — Task type relationships

5.3.3.7.2 Entity inheritance

- IfcRoot

5.3.3.7.3 Attributes

#	Attribute	Type	Description
IfcRoot (4)
1	GlobalId	IfcGloballyUniqueId	Assignment of a globally unique identifier within the entire software world.
2	OwnerHistory	OPTIONAL 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 is stored - either as addition, deletion or modification. IFC4-CHANGE The attribute has been changed to be OPTIONAL.
3	Name	OPTIONAL 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.
4	Description	OPTIONAL IfcText	Optional description, provided for exchanging informative comments.
IfcObjectDefinition (7)
	HasAssignments	SET [0:?] OF IfcRelAssigns FOR RelatedObjects	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.
	Nests	SET [0:1] OF IfcRelNests FOR RelatedObjects	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 structures only). IFC4-CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
	IsNestedBy	SET [0:?] OF IfcRelNests FOR RelatingObject	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). IFC4-CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	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. IFC4-CHANGE The inverse attribute datatype has been added.
	IsDecomposedBy	SET [0:?] OF IfcRelAggregates FOR RelatingObject	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 definition can be aggregated by several other objects (occurrences or parts). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	Decomposes	SET [0:1] OF IfcRelAggregates FOR RelatedObjects	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 definition can only be part of a single decomposition (to allow hierarchical structures only). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	HasAssociations	SET [0:?] OF IfcRelAssociates FOR RelatedObjects	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.
IfcTypeObject (3)
5	ApplicableOccurrence	OPTIONAL IfcIdentifier	The attribute optionally defines the data type of the occurrence object, to which the assigned type object can relate. If not present, no instruction is given to which occurrence object the type object is applicable. The following conventions are used: The IFC entity name of the applicable occurrence using the IFC naming convention, CamelCase with "Ifc" prefix It can be optionally followed by the predefined type after the separator "/" (forward slash), using uppercase If one type object is applicable to many occurrence objects, then those occurrence object names should be separate by comma "," forming a comma separated string. EXAMPLE Referring to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', referring to a brace as applicable entity would be expressed as 'IfcMember/BRACE'.
6	HasPropertySets	OPTIONAL SET [1:?] OF IfcPropertySetDefinition	Set of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type. IFC2x3-CHANGE The attribute aggregate type has been changed from LIST to SET.
	Types	SET [0:1] OF IfcRelDefinesByType FOR RelatingType	Reference to the relationship IfcRelDefinesByType and thus to those occurrence objects, which are defined by this type.
IfcTypeProcess (4)
7	Identification	OPTIONAL IfcIdentifier	An identifying designation given to a process type.
8	LongDescription	OPTIONAL IfcText	A long description, or text, describing the activity in detail. NOTE The inherited SELF\IfcRoot.Description attribute is used as the short description.
9	ProcessType	OPTIONAL IfcLabel	The type denotes a particular type that indicates the process 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.
	OperatesOn	SET [0:?] OF IfcRelAssignsToProcess FOR RelatingProcess	Set of relationships to other objects, e.g. products, processes, controls, resources or actors that are operated on by the process type. HISTORY New inverse relationship in IFC4.
Click to show 18 hidden inherited attributes
IfcTaskType (2)
10	PredefinedType	IfcTaskTypeEnum	Identifies the predefined types of a task type from which the type required may be set.
11	WorkMethod	OPTIONAL IfcLabel	The method of work used in carrying out a task.

Table 5.3.3.7.B

5.3.3.7.4 Formal propositions

Name	Description
CorrectPredefinedType	The attribute ProcessType must be asserted when the value of PredefinedType is set to USERDEFINED.
`(PredefinedType <> IfcTaskTypeEnum.USERDEFINED) OR ((PredefinedType = IfcTaskTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcTypeProcess.ProcessType))`

Table 5.3.3.7.C

5.3.3.7.5 Property sets

Pset_PackingInstructions MOVE
- PackingCareType
- WrappingMaterial
- ContainerMaterial
- SpecialInstructions
Pset_Risk
- RiskName
- RiskType
- NatureOfRisk
- RiskAssessmentMethodology
- UnmitigatedRiskLikelihood
- UnmitigatedRiskConsequence
- UnmitigatedRiskSignificance
- MitigationPlanned
- MitigatedRiskLikelihood
- MitigatedRiskConsequence
- MitigatedRiskSignificance
- MitigationProposed
- AssociatedProduct
- AssociatedActivity
- AssociatedLocation

5.3.3.7.6 Concept usage

Concept	Usage	Description
IfcRoot (2)
Revision Control	General	Ownership, history, and merge state is captured using IfcOwnerHistory.
Software Identity	General	IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
IfcObjectDefinition (9)
Classification Association	General	Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.
Aggregation	General	No description available.
Approval Association	General	No description available.
Constraint Association	General	No description available.
Document Association	General	No description available.
Library Association	General	No description available.
Material Association	General	No description available.
Material Single	General	No description available.
Nesting	General	No description available.
IfcTypeObject (2)
Object Type Predefined Type	General	No description available.
Property Sets for Types	General	No description available.
IfcTypeProcess (2)
Process Type Assignment	General	No description available.
Property Sets for Objects	General	This concept can be applied to the following resources: Pset_Risk
Click to show 15 hidden inherited concepts
IfcTaskType (2)
Object Nesting	General	IfcTaskType may nest other IfcTaskType or IfcTask entities using the IfcRelNests relationship. Such nesting indicates decomposed level of detail. Nesting of IfcTask entities is used if a task type shall be detailed by a sequence of tasks or if there is a need to include additional time information such as the duration of subtasks. Please note that IfcTask entities being contained within an IfcTaskType are linked with their task occurrences via IfcRelDefinesByObject relationships. It is also possible to define a task type for these IfcTask entities via IfcRelDefinesByType relationships. For further information please see the documentation of IfcRelDefinesByObject. This concept can be applied to the following resources: IfcTask
Property Sets for Objects	General	This is a further elaboration on an inherited concept. This concept can be applied to the following resources: Pset_PackingInstructions (only applies to `MOVE)`

Table 5.3.3.7.D

5.3.3.7.7 Formal representation

 ENTITY IfcTaskType
 SUBTYPE OF (IfcTypeProcess);
	PredefinedType : IfcTaskTypeEnum;
	WorkMethod : OPTIONAL IfcLabel;
 WHERE
	CorrectPredefinedType : (PredefinedType <> IfcTaskTypeEnum.USERDEFINED) OR ((PredefinedType = IfcTaskTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcTypeProcess.ProcessType));
END_ENTITY;

5.3.3.7.8 References

IfcTypeProcess