An IfcProcedure is a logical set of actions to be taken in response to an event or to cause an event to occur.

HISTORY  New entity in IFC2x2
IFC4 CHANGE  ProcedureType renamed to PredefinedType and made optional (upward compatible). Where rules WR1 and WR2 have been removed.

Use definitions

IfcProcedure is used to capture information about stepped processes such as calibration, start/stop procedures for equipment items, designated actions to take in the event of an emergency etc. A procedure is not a task, but may describe a set of tasks and their order of occurrence in response to or to cause an event.

As shown in Figure 11, IfcProcedure does not restrict anything but describes specific steps of how something should happen. While a procedure does control/restrict in the sense of indicating "this is how the task should be performed" by nature of describing inner detail, this is not different than parts of a product indicating "this is how the parts should be assembled". Consequently, it doesn't restrict the outer item as a whole but provides inner detail of the item.

procedure example

Figure 103 — Procedure relationships

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 12.

Table 12 — IfcProcedure Object Typing

IfcProcedure defines the anticipated or actual occurrence of any procedure; common information about procedure types is handled by IfcProcedureType.

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 13.

Table 13 — IfcProcedure Property Sets for Objects

Object Nesting

The Object Nesting concept applies to this entity.

The IfcProcedure may be contained within an IfcTask or IfcProcedure using the IfcRelNests relationship. An IfcProcedure may in turn nest other IfcProcedure or IfcEvent entities. Such nesting indicates decomposed level of detail.

Sequential Connectivity

The Sequential Connectivity concept applies to this entity.

The relationship IfcRelSequence is used to indicate control flow. An IfcProcedure as a successor to an IfcEvent indicates that the procedure should be performed in response to the event. An IfcProcedure as a predecessor to an IfcEvent indicates that the event should be trigerred following the procedure. As procedures have arbitrary duration, the IfcRelSequence.SequenceType attribute has no effect on an IfcProcedure but still applies to the opposite end of the relationship if IfcTask is used.

Process Assignment

The Process Assignment concept applies to this entity.

NOTE  A particular type of IfcProcedure is a caution, warning or other form of advisory note. Typically, it is anticipated that such a procedure would be assigned to the specific IfcProcess for which it gives advice using IfcRelAssignsToProcess.

Control Assignment

The Control Assignment concept applies to this entity.

An IfcProcedure may be assigned to an IfcWorkCalendar to indicate times when such procedure may be performed using IfcRelAssignsToControl; otherwise the effective calendar is determined by the nearest IfcProcess ancestor with a calendar assigned. Advisory notes should be assigned to the specific IfcProcess for which it gives advice using IfcRelAssignsToProcess.

Product Assignment

The Product Assignment concept applies to this entity.

For building operation scenarios, IfcProcedure may be assigned to a product (IfcElement subtype) using IfcRelAssignsToProduct to indicate a specific product occurrence that performs the procedure.

EXAMPLE  An IfcActuator may have a "Close" procedure. If the IfcProcedure is defined by an IfcProcedureType and the IfcProcedureType is assigned to a product type (using IfcRelAssignsToProduct), then the IfcProcedure must be assigned to one or more occurrences of the specified product type using IfcRelAssignsToProduct.

XSD Specification:

 <xs:element name="IfcProcedure" type="ifc:IfcProcedure" substitutionGroup="ifc:IfcProcess" nillable="true"/>
 <xs:complexType name="IfcProcedure">
   <xs:extension base="ifc:IfcProcess">
    <xs:attribute name="PredefinedType" type="ifc:IfcProcedureTypeEnum" use="optional"/>

EXPRESS Specification:

ENTITY IfcProcedure
SUBTYPE OF IfcProcess;
PredefinedType : OPTIONAL IfcProcedureTypeEnum;
HasName : EXISTS(SELF\IfcRoot.Name);
CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcProcedureTypeEnum.USERDEFINED) OR ((PredefinedType = IfcProcedureTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType));

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

PredefinedType : Identifies the predefined types of a procedure from which the type required may be set.

Formal Propositions:

HasName : The Name attribute should be inserted to describe the task name.
CorrectPredefinedType : Either the PredefinedType attribute is unset, or the inherited attribute ObjectType must be asserted when the value of PredefinedType is set to USERDEFINED.

Inheritance Graph:

ENTITY IfcProcedure
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
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;
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;
IsPredecessorTo : SET OF IfcRelSequence FOR RelatingProcess;
IsSuccessorFrom : SET OF IfcRelSequence FOR RelatedProcess;
OperatesOn : SET OF IfcRelAssignsToProcess FOR RelatingProcess;
ENTITY IfcProcedure
PredefinedType : OPTIONAL IfcProcedureTypeEnum;

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