| additions | where_rules | CorrectPredefinedType |
| additions | where_rules | HasName |
| deletions | attributes | ProcedureType |
| deletions | attributes | UserDefinedProcedureType |
| deletions | where_rules | WR1 |
| deletions | where_rules | WR2 |
| deletions | where_rules | WR3 |
| deletions | where_rules | WR4 |
| modifications | attributes ProcedureID definition | Changed from IfcIdentifier to IfcProcedureTypeEnum |
| modifications | attributes ProcedureID is_optional | Changed from False to True |
| modifications | attributes ProcedureID name | Changed from ProcedureID to PredefinedType |
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.

| # | 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. | |
| 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 | 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 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. | |
| IfcProcess | |||
| 6 | Identification | OPTIONAL IfcIdentifier | An identifying designation given to a process or activity. It is the identifier at the occurrence level. > IFC4 CHANGE Attribute promoted from subtypes. |
| 7 | LongDescription | OPTIONAL IfcText | An extended description or narrative that may be provided. > IFC4 CHANGE New attribute. |
| IsPredecessorTo | SET [0:?] OF IfcRelSequence FOR RelatingProcess | Dependency between two activities, it refers to the subsequent activity for which this activity is the predecessor. The link between two activities can include a link type and a lag time. | |
| IsSuccessorFrom | SET [0:?] OF IfcRelSequence FOR RelatedProcess | Dependency between two activities, it refers to the previous activity for which this activity is the successor. The link between two activities can include a link type and a lag time. | |
| OperatesOn | SET [0:?] OF IfcRelAssignsToProcess FOR RelatingProcess | Set of relationships to other objects, e.g. products, processes, controls, resources or actors, that are operated on by the process. | |
| IfcProcedure | |||
| 8 | PredefinedType | OPTIONAL IfcProcedureTypeEnum | Identifies the predefined types of a procedure from which the type required may be set. |
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.
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.
IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.
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.
IfcProcedure defines the anticipated or actual occurrence of any procedure; common information about procedure types is handled by IfcProcedureType.
| RelatingType |
|---|
| 'IfcProcedureType' |
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.
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.
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.
| PsetName |
|---|
| 'Pset_Risk' |
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.
Ownership, history, and merge state is captured using IfcOwnerHistory.
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.
ENTITY IfcProcedure SUBTYPE OF (IfcProcess); PredefinedType : OPTIONAL IfcProcedureTypeEnum; WHERE HasName : EXISTS(SELF\IfcRoot.Name); CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcProcedureTypeEnum.USERDEFINED) OR ((PredefinedType = IfcProcedureTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType)); END_ENTITY;