IfcTaskType

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcTaskType			ADDED

Semantic definitions at the entity

Entity definition

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

HISTORY New entity in IFC4

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 explict attributes of IfcTaskType. Task occurrences (IfcTask entities) are linked to the task type through the IfcRelDefinesByType relationship.

Figure 131 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.

Figure 131 — Task type relationships

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
10	PredefinedType	IfcTaskTypeEnum	[1:1]	Identifies the predefined types of a task type from which the type required may be set.	X
11	WorkMethod	IfcLabel	[0:1]	The method of work used in carrying out a task.	X

Formal Propositions

Rule	Description
CorrectPredefinedType	The attribute ProcessType must be asserted when the value of PredefinedType is set to USERDEFINED.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	[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
3	Name	IfcLabel	[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
4	Description	IfcText	[0:1]	Optional description, provided for exchanging informative comments.	X
IfcObjectDefinition
	HasAssignments	IfcRelAssigns @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
	Nests	IfcRelNests @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
	IsNestedBy	IfcRelNests @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
	HasContext	IfcRelDeclares @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
	IsDecomposedBy	IfcRelAggregates @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
	Decomposes	IfcRelAggregates @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
	HasAssociations	IfcRelAssociates @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
IfcTypeObject
5	ApplicableOccurrence	IfcIdentifier	[0:1]	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 Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.	X
6	HasPropertySets	IfcPropertySetDefinition	S[1:?]	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.	X
	Types	IfcRelDefinesByType @RelatingType	S[0:1]	Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.	X
IfcTypeProcess
7	Identification	IfcIdentifier	[0:1]	An identifying designation given to a process type.	X
8	LongDescription	IfcText	[0:1]	An long description, or text, describing the activity in detail. NOTE The inherited SELF\IfcRoot.Description attribute is used as the short description.	X
9	ProcessType	IfcLabel	[0:1]	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.	X
	OperatesOn	IfcRelAssignsToProcess @RelatingProcess	S[0:?]	Set of relationships to other objects, e.g. products, processes, controls, resources or actors that are operated on by the process type.	X
IfcTaskType
10	PredefinedType	IfcTaskTypeEnum	[1:1]	Identifies the predefined types of a task type from which the type required may be set.	X
11	WorkMethod	IfcLabel	[0:1]	The method of work used in carrying out a task.	X

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Object Nesting

The Object Nesting concept applies to this entity.

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.

Concept inheritance

#	Concept	Model View
IfcRoot
	Software Identity	Common Use Definitions
	Revision Control	Common Use Definitions
IfcTaskType
	Object Nesting	Common Use Definitions

Formal representations

XSD Specification

 <xs:element name="IfcTaskType" type="ifc:IfcTaskType" substitutionGroup="ifc:IfcTypeProcess" nillable="true"/>

 <xs:complexType name="IfcTaskType">

  <xs:complexContent>

   <xs:extension base="ifc:IfcTypeProcess">

    <xs:attribute name="PredefinedType" type="ifc:IfcTaskTypeEnum" use="optional"/>

    <xs:attribute name="WorkMethod" type="ifc:IfcLabel" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


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;

 EXPRESS-G diagram

Link to this page

	Aufgabe - Typ
	Task Type
	Type de tâche