5.3.3.1 IfcEvent

Evènement
Ereignis

An IfcEvent is something that happens that triggers an action or response.

HISTORY  New entity in IFC4

Use definitions

IfcEvent is used to capture information about particular things that happen or that may happen. Particularly used in work plans (or process maps) they identify e.g. a point at which a message containing information may be issued or at which a rule or constraint is invoked.


Common Use Definitions

The following concepts are inherited at supertypes:

 Instance diagram

Object Typing

The Object Typing concept applies to this entity as shown in Table 10.
Type
IfcEventType

Table 10 — IfcEvent Object Typing

The IfcEvent defines the anticipated or actual occurrence of any event; common information about event types is handled by IfcEventType.



Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 11.
PredefinedTypeName
 Pset_Risk

Table 11 — IfcEvent Property Sets for Objects



Object Nesting

The Object Nesting concept applies to this entity.

IfcEvent may be contained within an IfcTask using the IfcRelNests relationship. The event is considered active during the time period of the enclosing task (including any assigned IfcWorkCalendar); that is such event may be triggered within the task time period but not outside of it. As an IfcEvent is considered to be atomic, no use is anticipated for nesting processes inside the event.



Sequential Connectivity

The Sequential Connectivity concept applies to this entity.

The relationship IfcRelSequence is used to indicate control flow. An IfcEvent as a predecessor (IfcRelSequence.RelatingProcess) indicates that the succeeding process (typically IfcProcedure or IfcTask) is triggered in response to the event. An IfcEvent as a successor (IfcRelSequence.RelatedProcess) indicates that the completion of the preceeding process causes the event to be triggered. As events have zero duration, the IfcRelSequence.SequenceType attribute has no effect on an IfcEvent but still applies to the opposite end of the relationship if IfcTask is used.



Control Assignment

The Control Assignment concept applies to this entity.

An IfcEvent may be assigned to an IfcWorkCalendar to indicate times when such event is active using IfcRelAssignsToControl; otherwise the effective calendar is determined by the nearest IfcProcess ancestor with a calendar assigned.



Product Assignment

The Product Assignment concept applies to this entity.

For building operation scenarios, IfcEvent may be assigned to a product (IfcElement subtype) using IfcRelAssignsToProduct to indicate a specific product occurrence that sources the event.

EXAMPLE  An IfcSensor for a motion sensor may have a "Motion Sensed" event. If the IfcEvent is defined by an IfcEventType and the IfcEventType is assigned to a product type (using IfcRelAssignsToProduct), then the IfcEvent must be assigned to one or more occurrences of the specified product type using IfcRelAssignsToProduct.



XSD Specification:

 <xs:element name="IfcEvent" type="ifc:IfcEvent" substitutionGroup="ifc:IfcProcess" nillable="true"/>
 <xs:complexType name="IfcEvent">
  <xs:complexContent>
   <xs:extension base="ifc:IfcProcess">
    <xs:sequence>
     <xs:element name="EventOccurenceTime" type="ifc:IfcEventTime" nillable="true" minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="PredefinedType" type="ifc:IfcEventTypeEnum" use="optional"/>
    <xs:attribute name="EventTriggerType" type="ifc:IfcEventTriggerTypeEnum" use="optional"/>
    <xs:attribute name="UserDefinedEventTriggerType" type="ifc:IfcLabel" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcEvent
SUBTYPE OF IfcProcess;
PredefinedType : OPTIONAL IfcEventTypeEnum;
EventTriggerType : OPTIONAL IfcEventTriggerTypeEnum;
UserDefinedEventTriggerType : OPTIONAL IfcLabel;
EventOccurenceTime : OPTIONAL IfcEventTime;
WHERE
CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcEventTypeEnum.USERDEFINED) OR ((PredefinedType = IfcEventTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType));
CorrectTypeAssigned : NOT(EXISTS(EventTriggerType)) OR (EventTriggerType <> IfcEventTriggerTypeEnum.USERDEFINED) OR ((EventTriggerType = IfcEventTriggerTypeEnum.USERDEFINED) AND EXISTS(UserDefinedEventTriggerType));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

PredefinedType : Identifies the predefined types of an event from which the type required may be set.
EventTriggerType : Identifies the predefined types of event trigger from which the type required may be set.
UserDefinedEventTriggerType : A user defined event trigger type, the value of which is asserted when the value of an event trigger type is declared as USERDEFINED.
EventOccurenceTime : The date and/or time at which an event occurs.

Formal Propositions:

CorrectPredefinedType : Either the PredefinedType attribute is unset, or the inherited attribute ObjectType must be asserted when the value of PredefinedType is set to USERDEFINED.
CorrectTypeAssigned : Either the EventTriggerType attribute is unset, or the attribute UserDefinedEventTriggerType must be asserted when the value of EventTriggerType is set to USERDEFINED.

Inheritance Graph:

ENTITY IfcEvent
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
INVERSE
HasAssignments : SET OF IfcRelAssigns FOR RelatedObjects;
Nests : SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy : SET OF IfcRelNests FOR RelatingObject;
HasContext : SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy : SET OF IfcRelAggregates FOR RelatingObject;
Decomposes : SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations : SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject
ObjectType : OPTIONAL IfcLabel;
INVERSE
IsDeclaredBy : SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares : SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy : SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy : SET OF IfcRelDefinesByProperties FOR RelatedObjects;
ENTITY IfcProcess
Identification : OPTIONAL IfcIdentifier;
LongDescription : OPTIONAL IfcText;
INVERSE
IsPredecessorTo : SET OF IfcRelSequence FOR RelatingProcess;
IsSuccessorFrom : SET OF IfcRelSequence FOR RelatedProcess;
OperatesOn : SET OF IfcRelAssignsToProcess FOR RelatingProcess;
ENTITY IfcEvent
PredefinedType : OPTIONAL IfcEventTypeEnum;
EventTriggerType : OPTIONAL IfcEventTriggerTypeEnum;
UserDefinedEventTriggerType : OPTIONAL IfcLabel;
EventOccurenceTime : OPTIONAL IfcEventTime;
END_ENTITY;

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