Specification for IfcProcessExtension

EXPRESS Definition

EXPRESS-G Diagram

Table of contents

• Schema Semantic Definition
• Simple Types
• Select Types
• Enumerations
• Class Definitions
• Functions

Simple Types

No Simple Types defined in this Schema

Select Types

No Select Types defined in this Schema

Enumerations

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

M	IfcMultiplierOrDivider
W	IfcWorkPlanPurposeEnum IfcWorkTaskMilestoneEnum IfcWorkTaskStatusEnum

Class Definitions

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

R	IfcRelNestsProcesses IfcRelNestsWorkScheduleElements IfcRelNestsWorkSchedules IfcRelUsesResource
S	IfcScheduleTimeControl
W	IfcWorkPlan IfcWorkSchedule IfcWorkScheduleElement IfcWorkTask

Functions

No Functions defined in this Schema

Schema Semantic Definition

The models in the IfcProcessExtension schema allow for the capture of information concerning the work and construction resource uses in the process required in order to create a product. The schema also contains classes that represent work plans, work schedules and schedule elements. Relationships of these objects are also captured.

The schedule information identifies the time that a work task or a work plan may be scheduled to take to complete.

HISTORY: existing schema from R1.5.1

Type IfcMultiplierOrDivider

EXPRESS Definition

Type Semantic Definition

History

New Enumeration in IFC Release 2.0

Enumeration

Multiplier

Divider

Type IfcWorkPlanPurposeEnum

EXPRESS Definition

Type Semantic Definition

History

New Enumeration in IFC Release 2.0

Enumeration

CostEstimating

TaskScheduling

UserDefined

NotDefined

Type IfcWorkTaskMilestoneEnum

EXPRESS Definition

Type Semantic Definition

History

New Enumeration in IFC Release 2.0

Enumeration

StartMilestone

FinishMilestone

ScheduledMilestone

ContractMilestone

CustomerMilestone

SupplyMilestone

ManagementMilestone

FinancialMilestone

UserDefined

NotDefined

Type IfcWorkTaskStatusEnum

EXPRESS Definition

Type Semantic Definition

History

This Enumeration has changed after IFC Release 1.5.1, please see the Migration Guide for details

Enumeration

Completed

Started

NotYetStarted

UserDefined

NotDefined

Class IfcRelNestsProcesses

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

This class represents the relationships of a process (i.e. IfcProcess) that nests other processes as sub-processes. It stipulates that the nesting and nested objects must be of type IfcProcess. IfcRelNestsProcesses is a subtype of IfcRelNests.

History

This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
: existing class from R1.5.1
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcRelationship
 IfcRelNests
 IfcRelNestsProcesses

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
OPT	Criteria		STRING	The criteria of nesting processes.

Formal Propositions

WR41	Nesting object must be of type IfcProcess.
	('IFCKERNEL.IFCPROCESS' IN TYPEOF(SELF\IfcRelNests.RelatingObject))
WR42	Nesting objects must be of type IfcProcess.
	SIZEOF(QUERY(temp <* SELF\IfcRelNests.RelatedObjects | NOT('IFCKERNEL.IFCPROCESS' IN TYPEOF(temp)))) = 0

Informal Propositions

IP31	The IfcRelNests relationship shall be defined acyclic.

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcRelNestsWorkScheduleElements

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

IfcRelNestsWorkScheduleElements class represents the nesting relationships of a work schedule element (i.e. IfcWorkScheduleElement) nesting other work schedule elements as sub-items. It stipulates that the nesting and nested items must be of type IfcWorkScheduleElement. IfcRelNestsWorkScheduleElements is a subtype of IfcRelNests.

History

New Class in IFC Release 2.0
: new class for R2.0
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcRelationship
 IfcRelNests
 IfcRelNestsWorkScheduleElements

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
OPT	Description		STRING	Any description that would be useful to understand the nesting of the schedules.

Formal Propositions

WR41	Nesting object must be of type IfcWorkScheduleElement.
	('IFCPROCESSEXTENSION.IFCWORKSCHEDULEELEMENT' IN TYPEOF(SELF\IfcRelNests.RelatingObject))
WR42	Nesting objects must be of type IfcWorkScheduleElement.
	SIZEOF(QUERY(temp <* SELF\IfcRelNests.RelatedObjects | NOT('IFCPROCESSEXTENSION.IFCWORKSCHEDULEELEMENT' IN TYPEOF(temp)))) = 0

Informal Propositions

IP31	The IfcRelNests relationship shall be defined acyclic.

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcRelNestsWorkSchedules

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

IfcRelNestsWorkSchedule class represents the nesting relationships of a work schedule (i.e. IfcWorkSchedule) nesting other work schedules as sub-items. It stipulates that the nesting and nested objects must be of type IfcWorkSchedule. IfcRelNestsWorkSchedules is a subtype of IfcRelNests.

History

New Class in IFC Release 2.0
: new class from R2.0
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcRelationship
 IfcRelNests
 IfcRelNestsWorkSchedules

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
OPT	Description		STRING	Any description that would be useful to understand the nesting of the schedules.

Formal Propositions

WR41	Nesting object must be of type IfcWorkSchedule.
	('IFCPROCESSEXTENSION.IFCWORKSCHEDULE' IN TYPEOF(SELF\IfcRelNests.RelatingObject))
WR42	Nesting objects must be of type IfcWorkSchedule.
	SIZEOF(QUERY(temp <* SELF\IfcRelNests.RelatedObjects | NOT('IFCPROCESSEXTENSION.IFCWORKSCHEDULE' IN TYPEOF(temp)))) = 0

Informal Propositions

IP31	The IfcRelNests relationship shall be defined acyclic.

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcRelUsesResource

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

IfcRelUsesResource represents the use of a construction resource in a process. It specifies the duration, the costs, the quantity, and the waste factor of the resource used in the process. It also specifies a value of the process productivity conversion rate in order to calculate the resource use costs. IfcRelUsesResource is a subtype of IfcRelRelationship.

History

New Class in IFC Release 2.0
: new class from R2.0
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcRelationship
 IfcRelUsesResource

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
	RelatingProcess		IfcProcess	the process that requires the resource
	RelatedResource		IfcResource	the resources required by the process
OPT	Duration		IfcTimeMeasure	the time duration of the resource being used by the process
OPT	Quantity		IfcMeasureWithUnit	The total quantity of resource used by the process
OPT	ProductivityConversionRate		IfcMeasureWithUnit	The productivity conversion rate
OPT	ConverterMultiplierOrDivider		IfcMultiplierOrDivider	Indicates whether the productivity converstion rate serves a multiplier or divider.
	ResourceUseCosts		SET [0:?] OF IfcCostElement	The costs of the use of the resource in a process.
OPT	WasteFactor		REAL	The waste factor in percentage of the resource when used in the process.

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcScheduleTimeControl

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

This class represents the time-related information about a process. It captures the different types (i.e. actual, or scheduled) of starting and ending times, duration, floating times, and so on. IfcScheduleTimeControl is a subtype of IfcControl.

2. Renamed to IfcScheduleTimeControl in R2.0

History

New Class in IFC Release 2.0
: 1. Existing class in R1.5.1
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcObject
 IfcControl
 IfcScheduleTimeControl

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
OPT	ActualStart		IfcDateTimeSelect	The date on which a work task is actually started. NOTE - The scheduled start date must be greater than or equal to the earliest start date. No constraint is applied to the actual start date with respect to the scheduled start date since a work task may be started than had originally been scheduled if circumstances allow.
OPT	EarlyStart		IfcDateTimeSelect	The earliest date on which a work task can be started
OPT	LateStart		IfcDateTimeSelect	The latest date on which a work task can be started
OPT	ScheduleStart		IfcDateTimeSelect	The date on which a work task is scheduled to be started. NOTE - The scheduled start date must be greater than or equal to the earliest start date.
OPT	ActualFinish		IfcDateTimeSelect	The date on which a work task is actually finished
OPT	EarlyFinish		IfcDateTimeSelect	The earliest date on which a work task can be finishe
OPT	LateFinish		IfcDateTimeSelect	The latest date on which a work task can be finished
OPT	ScheduleFinish		IfcDateTimeSelect	The date on which a work task is scheduled to be finished. NOTE - The scheduled finish date must be greater than or equal to the earliest finish date.
OPT	ScheduleDuration		IfcTimeMeasure	The amount of time which is scheduled for completion of a work task. NOTE - Scheduled Duration may be calculated as the time from scheduled start date to scheduled finish date.
OPT	ActualDuration		IfcTimeMeasure	The actual duration of the process that attaches the time control data.
OPT	RemainingTime		IfcTimeMeasure	The amount of time remaining to complete a work task. NOTE - The time remaining in which to complete a work task may be determined both for tasks which have not yet started and those which have. Remaining time for a task not yet started has the same value as the scheduled duration. For a work task already started, remaining time is calculated as the difference between the scheduled finish and the point of analysis.
OPT	FreeFloat		IfcTimeMeasure	The amount of time during which the start or finish of a work task may be varied without any effect on the overall programme of work
OPT	TotalFloat		IfcTimeMeasure	The difference between the duration available to carry out a work task and the scheduled duration of the task. NOTE - Total Float time may be calculated as being the difference between the scheduled duration of a work task and the available duration from earliest start to latest finish. Float time may be either positive, zero or negative. Where it is zero or negative, the task becomes critical.
OPT	TaskStatus		IfcWorkTaskStatusEnum	Current status of the task. NOTE - A task may be not yet started, started (or partially complete) or completed. The actual value may be determined by comparison of the status time (which is the point at which analysis is undertaken) with start and finish dates as below. If StatusTime < ActualStart THEN IfcTaskStatusEnum := NotYetStarted. If StatusTime >= ActualStart AND StatusTime <= ActualEnd THEN IfcTaskStatusEnum := Started. If StatusTime > ActualEnd THEN IfcTaskStatusEnum := Completed
OPT	IsCritical		BOOLEAN	A flag which identifies whether a scheduled task is a critical item within the programme. NOTE - A work task becomes critical when the float time becomes zero or negative.
OPT	StatusTime		IfcDateTimeSelect	The date or time at which the status of the tasks within the programme is analysed.

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcWorkPlan

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

IfcWorkPlan class represents work plans in a construction or a facilities management project. A work plan contains a set of work schedules for different purposes. It also have references to all the activities (i.e. IfcWorkTask) and resources used in the work schedules. A work plan has information such as start date, finish date, total free float, and so on. IfcWorkPlan can also refer to the construction project represented by IfcProject through the IsContainedBy relationship to through IfcRelContains. IfcWorkPlan is a subtype of IfcControl.

History

New Class in IFC Release 2.0
: new class in R2.0.
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcObject
 IfcControl
 IfcWorkPlan

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
	PlanID		STRING	identifier of the work plan, given by user
	PlanName		STRING	Name of the work plan, given by user
OPT	Description		STRING	General description of the work plan
OPT	PlanPurpose		IfcWorkPlanPurposeEnum	Indicates the purpose of this work plan being made for.
	CreationDate		IfcDateTimeSelect	The date that the plan is created
	Creators		SET [0:?] OF IfcActorSelect	The authors of the work plan
	Tasks		SET [0:?] OF IfcWorkTask	The set of work tasks contained in the work plan. This is a mandatory relationship.
OPT	RootTask		IfcWorkTask	The root work task of the task hierarchy.
	Schedules		SET [0:?] OF IfcWorkSchedule	The set of work task schedules contained in the work plan.
	Resources		SET [0:?] OF IfcResource	All the types of resources used in the work plan. In the case that both this relationship and ‘Project’ and/or ‘ProjectPlan’, the user is responsible for ensuring that the instances of IfcResource referenced by the 3 relationships are consistent.

Formal Propositions

WR1	The work plan can be done for a particular project. Therefore a relationship to IfcProject is forseen by the IfcRelContains objectified relationship.
	SIZEOF(QUERY(Temp <* SELF\IfcObject.IsContainedBy | (Temp.RelationshipType = ProjectContainer) AND (Temp.ContainedOrReferenced = Referenced))) <= 1

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcWorkSchedule

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

IfcWorkSchedule class represents a work task schedule in a work plan, which in turn can contain a set of schedules for different purposes. A work schedule includes a set of work schedule elements (i.e. IfcWorkScheduleElement) with references to the resources used for the work tasks included in the work schedule through IfcWorkScheduleElement. Additionally, the schedulers can be specified. Schedule time information such as start time, finish time, and total float of the schedule can also be specified. A work schedule can also have a reference to a base schedule. IfcWorkSchedule can reference a project (i.e. IfcProject) through the containment relationship mechanism provided by IfcObject (i.e. IfcRelContains). The documents of the IfcWorkSchedule can be referenced by IfcDocumentReference through IfcObject. Moreover, a work schedule can include other work schedules as sub-items through IfcRelNestsWorkSchedules. IfcWorkSchedule is a subtype of IfcControl.

History

New Class in IFC Release 2.0
: new class in R2.0.
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcObject
 IfcControl
 IfcWorkSchedule

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
	WorkScheduleID		STRING	The ID of the work schedule.
	WorkScheduleName		STRING	The name of the work schedule.
OPT	Description		STRING	A description of the work schedule
OPT	WorkSchedulePurpose		STRING	A description of the purpose of the work schedule
	CreationDate		IfcDateTimeSelect	The date that the schedule is created
	Schedulers		SET [0:?] OF IfcActorSelect	The people who create the schedule
	ScheduleElements		SET [1:?] OF IfcWorkScheduleElement	A set of work schedule elemtns included in the schedule.
	TotalElements		INTEGER	The total number of schedule elements.
	Resources		SET [0:?] OF IfcResource	References to all the resources used by the work tasks in the schedule
OPT	BaseSchedule		IfcWorkSchedule	The reference to the base schedule
	StartTime		IfcDateTimeSelect	The start time of the schedule
OPT	FinishTime		IfcDateTimeSelect	The finish time of the schedule
OPT	Duration		IfcTimeMeasure	The total duration of the entire work schedule
OPT	TotalFloat		IfcTimeMeasure	The total time float of the entire work schedule
INV	WorkPlan		IfcWorkPlan	The work plan that the work schedule belongs to.

Formal Propositions

WR3	The work schedule can be done for a particular project. Therefore a relationship to IfcProject is forseen by the IfcRelContains objectified relationship.
	SIZEOF(QUERY(Temp <* SELF\IfcObject.IsContainedBy | (Temp.RelationshipType = ProjectContainer) AND (Temp.ContainedOrReferenced = Referenced))) <= 1
WR41	Restrict the relationship 'Nests' inherited from IfcObject to IfcRelNestsWorkSchedules.
	SIZEOF(QUERY(temp <* SELF\IfcObject.Nests | NOT('IFCPROCESSEXTENSION.IFCRELNESTSWORKSCHEDULES' IN TYPEOF(temp)))) = 0
WR42	Restrict the relationship 'IsNestedBy' inherited from IfcObject to IfcRelNestsWorkSchedules.
	SIZEOF(QUERY(temp <* SELF\IfcObject.IsNestedBy | NOT('IFCPROCESSEXTENSION.IFCRELNESTSWORKSCHEDULES' IN TYPEOF(temp)))) = 0

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcWorkScheduleElement

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

This class represents a work task element in a work schedule (i.e. IfcWorkSchedule). It is associated with a work task (i.e. IfcWorkTask) and attaches it to time schedule information (i.e. IfcScheduleTimeControl). A work schedule element can also include other schedule elements as sub-items. IfcWorkSchduleElement is a subtype of IfcControl.

History

New Class in IFC Release 2.0
: new class in R2.0.
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcObject
 IfcControl
 IfcWorkScheduleElement

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
	WorkTask		IfcWorkTask	The work task that the schedule element asigned to.
	TimeForSchedule		IfcScheduleTimeControl	Contained object for the time related information for the work schedule element
OPT	Milestone		IfcWorkTaskMilestoneEnum	The milestone of the work schedule element in the work schedule.
INV	WorkSchedule		IfcWorkSchedule	The work schedule that the element belongs to.

Formal Propositions

WR41	SIZEOF(QUERY(temp <* SELF\IfcObject.Nests | NOT('IFCPROCESSEXTENSION.IFCRELNESTSWORKSCHEDULEELEMENTS' IN TYPEOF(temp)))) = 0
WR42	SIZEOF(QUERY(temp <* SELF\IfcObject.IsNestedBy | NOT('IFCPROCESSEXTENSION.IFCRELNESTSWORKSCHEDULEELEMENTS' IN TYPEOF(temp)))) = 0

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.

Class IfcWorkTask

Fully Attributed View

EXPRESS Definition

Class Semantic Definition

An identifiable unit of work to be carried out independently of any other units of work in a construction project. Work is identified as work tasks (i.e. IfcWorkTask) that are capable of either containing other work tasks or being sub-items of other work tasks.

A work task can be used to describe a process for the construction or installation of products and is given a name that is indicative of its content. EXAMPLE: The installation of a number of items of equipment within a particular space may be the subject of a single work task which is identified as ‘fix equipment in space 123’.

IfcWorkTask represents the occurrence of a work performance of a type of process in a construction plan, while work task types themselves are not handled in this version. Each work can nest other work tasks as sub-items; the nesting relationship is modeled by IfcRelNestsProcesses. For example, the construction of a stud wall may be designated as a nesting work task named ‘install wall #1’ including other work tasks such as ‘install dry wall’, ‘install studs’, ‘wall taping’, and ‘erect wall’ as sub-processes. Additionally, the sequential relationships between work tasks are represented by IfcRelSequence in IfcKernel schema. Resource uses of work tasks are represented by IfcRelUsesResources. IfcWorkTask is a subtype of IfcProcess.

History

This Class has changed after IFC Release 1.5.1, please see the Migration Guide for details
: existing class from R1.5.1
ISSUE:

Attribute and Relationship Definitions

Superclasses and Subclasses

 IfcRoot
 IfcObject
 IfcProcess
 IfcWorkTask

Attributes and Relationships

Attribute type (OPT, DER, INV)		Redefinition (SELF)
	Attribute / Relation		Data or Rel. type	Definition
	WorkTaskID		STRING	An identifying designation given to a task.
	WorkTaskName		STRING	The name of the work task.
	WBSCode		LIST [0:?] OF STRING	The codes of the work breakdown structure implied to the type of the work task.
	WBSSource		LIST [0:?] OF STRING	The sources of the WBSs. The items in the list should be aligned to that of the WBSs
	Status		IfcWorkTaskStatusEnum	Current status of the task. NOTE - A task may be not yet started, started (or partially complete) or completed. The actual value may be determined by comparison of the status time (which is the point at which analysis is undertaken) with start and finish dates as below. If StatusTime < ActualStart THEN IfcTaskStatusEnum := NotYetStarted. If StatusTime >= ActualStart AND StatusTime <= ActualEnd THEN IfcTaskStatusEnum := Started. If StatusTime > ActualEnd THEN IfcTaskStatusEnum := Completed
	Milestones		SET [0:?] OF IfcWorkTaskMilestoneEnum	Indicates the milestones that this work task serves. One work task could be a milestone of different purposes in different plans.
OPT	WorkMethod		STRING	The method of work used in carrying out a task.
OPT	InPlaceQuantity		IfcMeasureWithUnit	The quantity that has been put in place by this work task.
OPT	EstimatedOuantity		IfcMeasureWithUnit	The estimated quantity that this work task is originally planned to complete.
OPT	BudgetQuantity		IfcMeasureWithUnit	The budget quantity that this work task is planned to complete based on actual resource available.
INV	ScheduleElements		SET [0:?] OF IfcWorkScheduleElement	The work schedule elements that associates with this work tasks.
INV	WorkPlans		SET [0:?] OF IfcWorkPlan	The reference to the work plan that contains the task

Formal Propositions

WR41	Restrict the relationship 'Nests' inherited from IfcObject to IfcRelNestsProcesses.
	SIZEOF(QUERY(temp <* SELF\IfcObject.Nests | NOT('IFCPROCESSEXTENSION.IFCRELNESTSPROCESSES' IN TYPEOF(temp)))) = 0
WR42	Restrict the relationship 'IsNestedBy' inherited from IfcObject to IfcRelNestsProcesses.
	SIZEOF(QUERY(temp <* SELF\IfcObject.IsNestedBy | NOT('IFCPROCESSEXTENSION.IFCRELNESTSPROCESSES' IN TYPEOF(temp)))) = 0

Geometry Use Definitions

Instances of this class have no physical presence and therefore no geometric representation.