## 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.

## 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

## 5.3.3.7.7 Formal representation

ENTITY IfcTaskType
SUBTYPE OF (IfcTypeProcess);
WorkMethod : OPTIONAL IfcLabel;
WHERE
END_ENTITY;