IFC 4.3.x development

5.3.3.8 IfcWorkCalendar

Change log

IFC4

added

5.3.3.8.1 Semantic definitions at the entity

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.

HISTORY  New entity in IFC4.

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 1 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 overriden 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"

5.3.3.8.1 Attributes

# Attribute Type Description
IfcRoot
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 in 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
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 strutures 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 definitions 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 definitions can only be part of a single decomposition (to allow hierarchical strutures only).

> IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
HasAssociationsSET [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 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.
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 had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
IsDefinedBy SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjectsSet 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
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.
IfcWorkCalendar
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

5.3.3.8.2 Entity inheritance

dot_inheritance IfcWorkCalendar IfcWorkCalendar IfcControl IfcControl IfcWorkCalendar->IfcControl IfcControl_children 7 more... IfcControl_children->IfcControl IfcObject IfcObject IfcControl->IfcObject IfcObject_children 5 more... IfcObject_children->IfcObject IfcObjectDefinition IfcObjectDefinition IfcObject->IfcObjectDefinition IfcContext IfcContext IfcContext->IfcObjectDefinition IfcRoot IfcRoot IfcObjectDefinition->IfcRoot IfcTypeObject IfcTypeObject IfcTypeObject->IfcObjectDefinition IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot IfcRelationship IfcRelationship IfcRelationship->IfcRoot

5.3.3.8.3 Definitions applying to General Usage

5.3.3.8.3.1 Classification Association

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.

5.3.3.8.3.2 Control Assignment

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.

5.3.3.8.3.3 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

5.3.3.8.3.4 Object Predefined Type

5.3.3.8.3.5 Object Typing

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.

5.3.3.8.3.6 Object User Identity

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.

5.3.3.8.3.7 Property Sets for Objects

Any object occurrence can hold property sets, each being a set of individual properties having name, description, value(s) and unit(s). A reference to applicable property sets, being part of this specification, is introduced at the level of sub types of IfcObject.

5.3.3.8.3.8 Property Sets with Override

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.

5.3.3.8.3.9 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

5.3.3.8.4 Formal representations

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;