5.3.3.2 IfcTask
An IfcTask is an identifiable unit of work to be carried out in a construction project.
A task is typically used to describe an activity for the construction or installation of products, but is not
limited to these types. For example it might be used to describe design processes, move operations and other
design, construction and operation related activities as well.
Quantities of resources
consumed by the task are dealt with by defining the
IfcElementQuantity for the resource and not at the
instance of IfcTask.
HISTORY New entity in IFC1.0. Renamed from IfcWorkTask in IFC2x.
IFC4 CHANGE Attributes TaskTime and PredefinedType added. IfcMove and IfcOrderRequest has been removed in IFC4 and are now represented by IfcTask. IfcRelAssignsTasks relationship has been
removed as well.
Attribute use definition
Each occurrence of IfcTask is given a name that is
indicative of its content (IfcRoot.Name). A textual
description of the task may be provided and this may be
further elaborated by a narrative long description
(IfcProcess.LongDescription). A work method may be
declared for the method of work used in carrying out a
task. A task is identified as being either a milestone task
or not. A milestone task is defined by the marker
IsMilestone. and has no duration. A status and
priority for each task may also be set.
Time and duration use definition
Compared to previous IFC releases, basic task time
information (scheduled start time, scheduled finish
time, duration) is now directly attached to IfcTask
through the TaskTime attribute. Regular tasks are
defined through IfcTaskTime. Recurring tasks are
defined through IfcTaskTimeRecurring. In case a
regular task is derived from a recurring task both tasks
should be linked together through a IfcRelNests
relationship, where IfcRelNests.IsNestedBy points to
the recurring task and IfcRelNests.Nests points to
all regular tasks that have been derived from the recurring
task.
Representation of other activities
The use definitions for IfcTask have been generalised to
represent other activities as well, including activities
that had been defined by own entities in previous IFC
releases. This includes
- Order actions
- Move operations
IfcTask represents an order that might be carried
out by a Helpdesk acting the role of interface for the
organization between the facility user and the functional
requirement of fulfilling their needs. The actual task
represented by the IfcTask entity is turning a
request into an order and initiating the action that will
enable the order to be completed. The
IfcProjectOrder or one of its subtypes including
maintenance work order, is related to the IfcTask
using IfcRelAssignsToControl.
IfcTask can also be used to describe an activity
that moves people, groups within an organization or
complete organizations together with their associated
furniture and equipment from one place to another. It thus
replaces the previous IFC entity IfcMove. The functionality
is represented in IfcTask as follows:
- Move from: The place from which actors and their
associated equipment are moving.
Use IfcRelAssignsToProcess where
RelatingProcess points to the task and
RelatedObjects holds the location(s) from which to
move.
- Move to: The place to which actors and their
associated equipment are moving.
Use IfcRelAssignsToProduct where
RelatedObjects points to the task(s) and
RelatingProduct points to the location to which to
move.
- Punch list: A list of points concerning a move that
require attention.
Use LongDescription or else identify sub-tasks to
track punch list items individually via IfcRelNests.
Construction Operations
Instance diagram
Identity
The Identity concept applies to this entity.
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
| Export |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
Revision Control
The Revision Control concept applies to this entity.
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
| Export |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
External Data Constraints
The External Data Constraints concept applies to this entity as shown in Table 9.
| Table | Name | Reference | Format | Color |
|---|
| Job | Name | IfcTask.Name | Key | #FFFF99 |
| Job | CreatedBy | IfcTask.OwnerHistory\IfcOwnerHistory.OwningUser\IfcPersonAndOrganization.ThePerson\IfcPerson.Identification | | #FFCC99 |
| Job | CreatedOn | IfcTask.OwnerHistory\IfcOwnerHistory.CreationDate | | #FFFF99 |
| Job | Category | IfcTask.IsDefinedBy['COBie_Task']\IfcRelDefinesByProperties.RelatingPropertyDefinition\IfcPropertySet.HasProperties['Category']\IfcPropertyEnumeratedValue.EnumerationValues['']\IfcLabel | | #FFCC99 |
| Job | Status | IfcTask.IsDefinedBy['COBie_Task']\IfcRelDefinesByProperties.RelatingPropertyDefinition\IfcPropertySet.HasProperties['Status']\IfcPropertyEnumeratedValue.EnumerationValues['']\IfcLabel | | #FFCC99 |
| Job | TypeName | IfcTask.HasAssignments[*]\IfcRelAssignsToProduct.RelatingProduct | Key | #FFCC99 |
| Job | Description | IfcTask.Description | | #FFFF99 |
| Job | Duration | IfcTask.TaskTime\IfcTaskTimeRecurring.ScheduleDuration | | #FFFF99 |
| Job | DurationUnit | | | #FFCC99 |
| Job | Start | IfcTask.TaskTime\IfcTaskTimeRecurring.ScheduleStart | | #FFFF99 |
| Job | TaskStartUnit | | | #FFCC99 |
| Job | Frequency | IfcTask.TaskTime\IfcTaskTimeRecurring.Recurrence\IfcRecurrencePattern.Interval | | #FFFF99 |
| Job | FrequencyUnit | IfcTask.TaskTime\IfcTaskTimeRecurring.Recurrence\IfcRecurrencePattern.RecurrenceType | | #FFCC99 |
| Job | ExtSystem | IfcTask.OwnerHistory.OwningApplication.ApplicationIdentifier | | #CC99FF |
| Job | ExtObject | IfcTask\ | | #CC99FF |
| Job | ExtIdentifier | IfcTask.GlobalId | | #CC99FF |
| Job | TaskNumber | IfcTask.Identification | Key | #CCFFCC |
| Job | Priors | IfcTask.IsSuccessorTo[*].RelatedObject | | #FFCC99 |
| Job | ResourceNames | IfcTask.OperatesOn[*]\IfcRelAssignsToProcess.RelatedObjects[*] | | #FFCC99 |
|
Table 9 — IfcTask External Data Constraints |
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
| Export |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
R |
Classification
The Classification concept applies to this entity as shown in Table 10.
| Source | Name | Tokens | Description |
|---|
| Construction Specifications Institute | OmniClass Table 31 | 31-00 00 00 | Phases |
|
Table 10 — IfcTask Classification |
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
| Export |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
Properties for Occurrences
The Properties for Occurrences concept applies to this entity as shown in Table 11.
|
|
Table 11 — IfcTask Properties for Occurrences |
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
| Export |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
Task Scheduling
The Task Scheduling concept applies to this entity.
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
| Export |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
Sequential Connectivity
The Sequential Connectivity concept applies to this entity.
| Exchange |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Import |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
| Export |
|
|
|
|
|
|
|
|
|
|
|
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
O |
XSD Specification:
<xs:element name="IfcTask" type="ifc:IfcTask" substitutionGroup="ifc:IfcProcess" nillable="true"/>
<xs:complexType name="IfcTask">
<xs:complexContent>
<xs:extension base="ifc:IfcProcess">
<xs:sequence>
<xs:element name="TaskTime" type="ifc:IfcTaskTime" nillable="true" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
EXPRESS Specification:
|
|
| Status | : | OPTIONAL IfcStrippedOptional; |
| WorkMethod | : | OPTIONAL IfcStrippedOptional; |
| IsMilestone | : | IfcStrippedOptional; |
| Priority | : | OPTIONAL IfcStrippedOptional; |
| TaskTime | : | OPTIONAL IfcTaskTime; |
| PredefinedType | : | OPTIONAL IfcStrippedOptional; |
|
|
|
| HasName | : | EXISTS(SELF\IfcRoot.Name); | | CorrectPredefinedType | : | NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcTaskTypeEnum.USERDEFINED) OR ((PredefinedType = IfcTaskTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType)); |
|
Attribute Definitions:
| Status | : |
Current status of the task.
NOTE Particular values for status are not
specified, these should be determined and agreed by local
usage. Examples of possible status values include 'Not Yet
Started', 'Started', 'Completed'.
|
| WorkMethod | : |
The method of work used in carrying out a task.
NOTE This attribute should
not be used if the work method is specified for the
IfcTaskType
|
| IsMilestone | : |
Identifies whether a task is a milestone task (=TRUE) or not
(= FALSE).
NOTE In small project planning applications,
a milestone task may be understood to be a task having no
duration. As such, it represents a singular point in time.
|
| Priority | : |
A value that indicates the relative priority of the task (in
comparison to the priorities of other tasks).
|
| TaskTime | : |
Time related information for the task.
IFC4 CHANGE Attribute added
|
Formal Propositions:
| HasName | : | The Name attribute should be inserted to describe the task name. |
| CorrectPredefinedType | : | The attribute ObjectType must be asserted when the value of PredefinedType is set to USERDEFINED. |
Inheritance Graph:
|
|
| ObjectType | : | OPTIONAL IfcStrippedOptional; |
|
|
|
| Identification | : | OPTIONAL IfcStrippedOptional; |
| LongDescription | : | OPTIONAL IfcStrippedOptional; |
|
|
|
| Status | : | OPTIONAL IfcStrippedOptional; |
| WorkMethod | : | OPTIONAL IfcStrippedOptional; |
| IsMilestone | : | IfcStrippedOptional; |
| Priority | : | OPTIONAL IfcStrippedOptional; |
| TaskTime | : | OPTIONAL IfcTaskTime; |
| PredefinedType | : | OPTIONAL IfcStrippedOptional; |
|
Link to this page