IFC 4.3.0.1 (IFC4X3_TC1)

5.3.3.7 IfcTaskType

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

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,

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 strutures only).

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).

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.

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 definitions can be aggregated by several other objects (occurrences or parts).

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 definitions can only be part of a single decomposition (to allow hierarchical strutures only).

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.

6 HasPropertySets OPTIONAL SET [1:?] OF IfcPropertySetDefinition

Set ~~list~~ of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type.

Types SET [0:1] OF IfcRelDefinesByType FOR RelatingType

Reference to the relationship IfcRelDefinedByType 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

An long description, or text, describing the activity in detail.

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.

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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)
Aggregation General

No description available.

Approval Association General

No description available.

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.

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 (1)
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:

Click to show 14 hidden inherited concepts Click to hide 14 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:

Property Sets for Objects General

This concept can be applied to the following resources:

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

5.3.3.7.9 Changelog

5.3.3.7.9.1 IFC4

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