5.3.3.8 IfcWorkCalendar

5.3.3.8.1 Semantic definition

An IfcWorkCalendar defines working and non-working time periods for tasks and resources. It enables to define both specific time periods, such as from 7:00 till 12:00 on 25th August 2009, as well as repetitive time periods based on frequently used recurrence patterns, such as each Monday from 7:00 till 12:00 between 1st March 2009 and 31st December 2009.

A work calendar is a subtype of IfcControl and thus inherits the feature for controlling other objects through IfcRelAssignsToControl, which is used to define a work calendar for tasks (IfcTask) and resources (IfcResource). It also inherits a name and description attribute, whereas a name shall be given and a description may be given as an indication of its content and usage.

The definition of time periods can be derived from a base calendar and/or modified/defined by a set of working times and non-working exception times. All time periods defined by IfcWorkCalendar.ExceptionTimes override the time periods inherited from the base calendar (base calendar is defined as the next applicable calendar for the task or resource). Thus, exception times replace the working times from the base calendar.

Figure 5.3.3.8.A shows the definition of a work calendar, which is defined by a set of work times and exception times. The work times are defined as recurring patterns with optional boundaries (applying from and/or to a specific date). The shown example defines a simple work calendar with working times Monday to Thursday 8:00 to 12:00 and 13:00 to 17:00, Friday 8:00 to 14:00 and as exception every 1st Monday in a month the work starts one hour later - i.e. the working time on every 1st Monday in a month is overridden to be 9:00 to 12:00 and 13:00 to 17:00. Both the working time and the exception time is valid for the period of 01.09.2010 till 30.08.2011.

task type instantiation diagram — Figure 5.3.3.8.A — Work calendar instantiation

5.3.3.8.2 Entity inheritance

5.3.3.8.3 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, NOTE Only the last modification is stored - either as addition, deletion or modification. IFC4-CHANGE The attribute has been changed to be OPTIONAL.
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 structures only). IFC4-CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
	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). IFC4-CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
	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. IFC4-CHANGE The inverse attribute datatype has been added.
	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 definition can be aggregated by several other objects (occurrences or parts). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	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 definition can only be part of a single decomposition (to allow hierarchical structures only). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	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.
IfcObject (5)
5	ObjectType	OPTIONAL IfcLabel	The type denotes a particular type that indicates the object 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 or when the concrete entity instantiated does not have a PredefinedType attribute. The latter is the case in some exceptional leaf classes and when instantiating IfcBuiltElement directly.
	IsDeclaredBy	SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects	Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. IFC4-CHANGE New inverse relationship, change made with upward compatibility for file based exchange.
	Declares	SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject	Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes. IFC4-CHANGE New inverse relationship, change made with upward compatibility for file based exchange.
	IsTypedBy	SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects	Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type. IFC4-CHANGE New inverse relationship, the link to IfcRelDefinesByType was previously included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
	IsDefinedBy	SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects	Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object. IFC4-CHANGE The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
IfcControl (2)
6	Identification	OPTIONAL IfcIdentifier	An identifying designation given to a control It is the identifier at the occurrence level. IFC4-CHANGE Attribute unified by promoting from various subtypes of IfcControl.
	Controls	SET [0:?] OF IfcRelAssignsToControl FOR RelatingControl	Reference to the relationship that associates the control to the object(s) being controlled.
Click to show 18 hidden inherited attributes
IfcWorkCalendar (3)
7	WorkingTimes	OPTIONAL SET [1:?] OF IfcWorkTime	Set of times periods that are regarded as an initial set-up of working times. Exception times can then further restrict these working times.
8	ExceptionTimes	OPTIONAL SET [1:?] OF IfcWorkTime	Set of times periods that define exceptions (non-working times) for the given working times including the base calendar, if provided.
9	PredefinedType	OPTIONAL IfcWorkCalendarTypeEnum	Identifies the predefined types of a work calendar from which the type required may be set. IFC4-CHANGE Attribute added

Table 5.3.3.8.C

5.3.3.8.4 Formal propositions

Name Description

CorrectPredefinedType

The attribute ObjectType must be asserted when the value of the IfcWorkCalendarTypeEnum is set to USERDEFINED.

 NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcWorkCalendarTypeEnum.USERDEFINED) OR
((PredefinedType = IfcWorkCalendarTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType))

Table 5.3.3.8.D

5.3.3.8.5 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)
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.
Aggregation	General	No description available.
Approval Association	General	No description available.
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.
IfcObject (5)
Object Predefined Type	General	No description available.
Object Typing	General	Any object occurrence can be typed by being assigned to a common object type utilizing this concept. A particular rule, restricting the applicable subtypes of IfcTypeObject that can be assigned, is introduced by overriding this concept at the level of subtypes of IfcObject. This concept can be applied to the following resources: IfcTypeObject
Object User Identity	General	An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as IfcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.
Property Sets with Override	General	Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case that the same property (within the same property set) is defined both in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.
Assignment to Group	General	No description available.
IfcControl (1)
Control Assignment	General	Controls have assignments from products, processes, or other objects by using the relationship object IfcRelAssignsToControl. This concept can be applied to the following resources: IfcObjectDefinition
Click to show 17 hidden inherited concepts
IfcWorkCalendar (1)
Control Assignment	General	This is a further elaboration on an inherited concept. The base calendar of a work calendar is defined by IfcRelAssignsToControl, where IfcRelAssignsToControl.RelatingControl is linked with the base calendar and IfcRelAssignsToControl.RelatedObjects is linked with work calendars that are derived from the base calendar. Although not restricted by the IfcRelAssignsToControl relationship it is only allowed to have one base calendar. This concept can be applied to the following resources: IfcEvent IfcProcedure IfcWorkCalendar IfcTask

Table 5.3.3.8.E

5.3.3.8.6 Examples

Figure 5.3.3.8.B

Construction Scheduling Task

5.3.3.8.7 Formal representation

 ENTITY IfcWorkCalendar
 SUBTYPE OF (IfcControl);
	WorkingTimes : OPTIONAL SET [1:?] OF IfcWorkTime;
	ExceptionTimes : OPTIONAL SET [1:?] OF IfcWorkTime;
	PredefinedType : OPTIONAL IfcWorkCalendarTypeEnum;
 WHERE
	CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcWorkCalendarTypeEnum.USERDEFINED) OR
((PredefinedType = IfcWorkCalendarTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType));
END_ENTITY;

5.3.3.8.8 References

IfcControl