IFC 4.3.x development

7.3.3.8 IfcConstructionResourceType

Change log

IFC4

added

7.3.3.8.1 Semantic definitions at the entity

IfcConstructionResourceType is an abstract generalization of the different resource types used in construction projects, mainly labor, material, equipment and product resource types, plus subcontracted resource types and aggregations such as a crew resource type.

A resource type represents a model of "use of something" and does not necessarily correspond to a specific type of object such as a person or vehicle, but represents possible usages of such objects such as general labor or an equipment fleet. A resource type can either represent usage in general (consumption attributes defined but no task type assignment) or a task-specific resource type (production attributes defined and having an IfcTask assignment).

A construction resource type captures common productivities and cost rates for applying resources to particular task types.

HISTORY  New entity in IFC4.

Composition use definition

Resource types may be decomposed into nested resource types indicating productivities when applying the resource to specific task types using the IfcRelNests relationship where IfcRelNests.RelatingObject refers to the general resource type and IfcRelNests.RelatedObjects refers to one or more task-specific productivities. For example, an IfcLaborResourceType may be defined for "Carpenter" which may have a nested IfcLaborResourceType for "Carpenter - Wall Framing" and another nested IfcLaborResourceType for "Carpenter - Drywall", each of which may have productivities based according to specific task types (IfcTaskType).

Assignment use definition

Resource types may be assigned to process types (IfcTypeProcess subtypes) using the IfcRelAssignsToProcess relationship as shown in Figure 1. Such relationship indicates that the resource type applies to the process type for the use indicated (e.g. IfcTaskType.PredefinedType). Such relationship enables a scenario of placing an IfcProduct of a particular IfcTypeProduct, querying for a set of IfcTypeProcess process types for constructing such product (e.g. IfcTaskTypeEnum.CONSTRUCTION), querying each IfcTypeProcess for a set of IfcTypeResource resource types for carrying out the process, and finally choosing an IfcTypeProcess and IfcTypeResource combination resulting in the shortest time for instantiated IfcTask occurrence(s) and/or lowest-cost for instantiated IfcConstructionResource occurrence(s).

"Assignment Use Definition"

7.3.3.8.1 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.
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.
IfcTypeObject
5 ApplicableOccurrenceOPTIONAL IfcIdentifier The attribute optionally defines the data type of the occurrence object, to which the assigned type object can relate. If not present, no instruction is given to which occurrence object the type object is applicable. The following conventions are used:

* The IFC entity name of the applicable occurrence using the IFC naming convention, CamelCase with IFC prefix

* It can be optionally followed by the predefined type after the separator "/" (forward slash), using uppercase

* If one type object is applicable to many occurrence objects, then those occurrence object names should be separate by comma "," forming a comma separated string.

> EXAMPLE Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.
6 HasPropertySets OPTIONAL SET [1:?] OF IfcPropertySetDefinition Set ~~list~~ of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type.

> IFC2x3 CHANGE  The attribute aggregate type has been changed from LIST to SET.
Types SET [0:1] OF IfcRelDefinesByType FOR RelatingType Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.
IfcTypeResource
7 Identification OPTIONAL IfcIdentifier An identifying designation given to a resource type.
8 LongDescription OPTIONAL IfcText An long description, or text, describing the resource in detail.

> NOTE  The inherited _SELF\IfcRoot.Description_ attribute is used as the short description.
9 ResourceType OPTIONAL IfcLabel The type denotes a particular type that indicates the resource 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.
ResourceOf SET [0:?] OF IfcRelAssignsToResource FOR RelatingResourceSet of relationships to other objects, e.g. products, processes, controls, resources or actors to which this resource type is a resource.

> HISTORY New inverse relationship in IFC4.
IfcConstructionResourceType
10 BaseCosts OPTIONAL LIST [1:?] OF IfcAppliedValue Indicates the unit costs and environmental impacts for which accrued amounts should be calculated. Such unit costs may be split into Name designations (e.g. 'Standard', 'Overtime'), and may contain a hierarchy of cost values that apply at different dates (using _IfcCostValue.ApplicableDate_ and _IfcCostValue.FixedUntilDate_).
11 BaseQuantity OPTIONAL IfcPhysicalQuantity Identifies the quantity for which the BaseQuantityProduced applies. The Name of the IfcPhysicalQuantity identifies the quantity definition being measured, e.g. "GrossVolume". For production-based resources (e.g. carpentry labor), this value refers to quantities on IfcProduct(s) to which the assigned IfcTask is assigned. For duration-based resources (e.g. safety inspector, fuel for equipment), this value refers to quantities that may be assigned to occurrences of the assigned IfcTaskType.

7.3.3.8.2 Entity inheritance

dot_inheritance IfcConstructionResourceType_children 5 more... IfcConstructionResourceType IfcConstructionResourceType IfcConstructionResourceType_children->IfcConstructionResourceType IfcTypeResource IfcTypeResource IfcConstructionResourceType->IfcTypeResource IfcTypeObject IfcTypeObject IfcTypeResource->IfcTypeObject IfcTypeProcess IfcTypeProcess IfcTypeProcess->IfcTypeObject IfcObjectDefinition IfcObjectDefinition IfcTypeObject->IfcObjectDefinition IfcTypeProduct IfcTypeProduct IfcTypeProduct->IfcTypeObject IfcContext IfcContext IfcContext->IfcObjectDefinition IfcRoot IfcRoot IfcObjectDefinition->IfcRoot IfcObject IfcObject IfcObject->IfcObjectDefinition IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot IfcRelationship IfcRelationship IfcRelationship->IfcRoot

7.3.3.8.3 Definitions applying to General Usage

7.3.3.8.3.1 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.

7.3.3.8.3.2 Identity

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

7.3.3.8.3.3 Revision Control

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

7.3.3.8.4 Formal representations

ENTITY IfcConstructionResourceType
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcConstructionEquipmentResourceType
	,IfcConstructionMaterialResourceType
	,IfcConstructionProductResourceType
	,IfcCrewResourceType
	,IfcLaborResourceType
	,IfcSubContractResourceType))
 SUBTYPE OF (IfcTypeResource);
	BaseCosts : OPTIONAL LIST [1:?] OF IfcAppliedValue;
	BaseQuantity : OPTIONAL IfcPhysicalQuantity;
END_ENTITY;