IfcCostItem

Natural language names
deKostenelement
enCost Item
frItem de coût
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcCostItem
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      IdentificationADDED
      PredefinedTypeADDED
      CostValuesADDED
      CostQuantitiesADDED
Semantic definitions at the entity
Entity definition

An IfcCostItem describes a cost or financial value together with descriptive information that describes its context in a form that enables it to be used within a cost schedule. An IfcCostItem can be used to represent the cost of goods and services, the execution of works by a process, lifecycle cost and more.

Each instance of IfcCostItem may have a name and a description. Depending on the use for which the cost is intended, these values should be asserted on the basis of agreement. For instance, the Name attribute could be used to provide a common value that enables distinct instances to be brought together in a nesting arrangement (see below) while the Description attribute may be used to provide text used for item description in a costing schedule.

An IfcCostItem can link one or many IfcCostValue's representing a unit cost, total cost, or a unit cost with one or many quantities used to generate the total cost. The quantities can be given as individual quantities, or those quantities are provided as element quantities by one or many building elements. The IfcCostValue.CostType attribute indicates the category of cost, which may be used to present the value in a particular column. For nested cost items (having IfcRelNests relationship), IfcCostValue.CostType is significant such that IfcCostValue.AppliedValue is calculated as the sum of all nested costs having the same IfcCostValue.CostType or if set to an asterisk ('*'), then the sum of all nested costs of all cost types. An IfcCostValue may represent an original value or a value derived from formulas using IfcAppliedValueRelationship. For example, taxes may be calculated as a percentage of a subtotal.

HISTORY  New entity in IFC2.0.
IFC4 CHANGE  Attribute PredefinedType, CostValues, and CostQuantities added.
Attribute definitions
#AttributeTypeCardinalityDescription B
7PredefinedTypeIfcCostItemTypeEnum[0:1] Predefined generic type for a cost item that is specified in an enumeration. There may be a property set given specificly for the predefined types. X
8CostValues- This attribute is out of scope for this model view definition and shall not be set.
9CostQuantities- This attribute is out of scope for this model view definition and shall not be set.
Inherited definitions from supertypes
Entity inheritance IfcControl IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionB
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[0:1] 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.
X
3NameIfcLabel[0:1] 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. X
4DescriptionIfcText[0:1] Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects		S[0:?]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.X
NestsIfcRelNests
@RelatedObjects		S[0:1]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).
IsNestedByIfcRelNests
@RelatingObject		S[0:?]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). X
HasContextIfcRelDeclares
@RelatedDefinitions		S[0:1]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.
IsDecomposedByIfcRelAggregates
@RelatingObject		S[0:?]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). X
DecomposesIfcRelAggregates
@RelatedObjects		S[0:1]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). X
HasAssociationsIfcRelAssociates
@RelatedObjects		S[0:?]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.X
IfcObject
5ObjectType- This attribute is out of scope for this model view definition and shall not be set.
IsTypedByIfcRelDefinesByType
@RelatedObjects		S[0:1]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. X
IsDefinedByIfcRelDefinesByProperties
@RelatedObjects		S[0:?]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. X
IfcControl
6Identification- This attribute is out of scope for this model view definition and shall not be set.
ControlsIfcRelAssignsToControl
@RelatingControl		S[0:?]Reference to the relationship that associates the control to the object(s) being controlled. X
IfcCostItem
7PredefinedTypeIfcCostItemTypeEnum[0:1] Predefined generic type for a cost item that is specified in an enumeration. There may be a property set given specificly for the predefined types. X
8CostValues- This attribute is out of scope for this model view definition and shall not be set.
9CostQuantities- This attribute is out of scope for this model view definition and shall not be set.
Definitions applying to Bridge View

 Instance diagram

Concept usage

Object Nesting

The Object Nesting concept applies to this entity as shown in Table 64.

Type
IfcCostItem

Table 64 — IfcCostItem Object Nesting

An IfcCostItem can nest other instances of IfcCostItem through its relationships to IfcRelNests. This can be used to enable the development of complex groups of costs as may be found in cost schedules through to pages, sections and complete cost schedules.

There is always a summary cost item as the root item of the tree representing the cost item nesting. Subsequent instances of IfcCostItem are assigned to the summary cost item using IfcRelNests. The summary cost item itself is assigned to IfcCostSchedule through the IfcRelAssignsToControl relationship.

Figure 202 illustrates a cost item composition used for a cost schedule. Each line item has a quantity and separate unit costs where IfcCostValue.CostType indicates the category of cost. The summary item has a hierarchy of costs calculated according to IfcAppliedValueRelationship.ArithmeticOperator, where IfcCostValue.CostType identifies the category to be totalled. The Tax component has IfcCostValue.CostType set to 'Material' which indicates it is the sum of all nested values of the 'Material' category ($3 x 3000 + $118 x 100 = $20800). The Subtotal component has IfcCostValue.CostType set to an asterisk ('*') which indicates it is the sum of all nested values of all categories.

cost item

Figure 202 — Cost composition

Exchange
Import O O
Export O O


Control Assignment

The Control Assignment concept applies to this entity as shown in Table 65.

TypeDescription
IfcElementElements assigned to quantity line item.

Table 65 — IfcCostItem Control Assignment

Exchange
Import R R
Export R R


Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityBridge View
User IdentityBridge View
Object OwnershipBridge View
IfcObject
Property Sets for ObjectsBridge View
IfcCostItem
Object NestingBridge View
Control AssignmentBridge View
Formal representations
XSD Specification
 <xs:element name="IfcCostItem" type="ifc:IfcCostItem" substitutionGroup="ifc:IfcControl" nillable="true"/>
 <xs:complexType name="IfcCostItem">
  <xs:complexContent>
   <xs:extension base="ifc:IfcControl">
    <xs:attribute name="PredefinedType" type="ifc:IfcCostItemTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcCostItem
 SUBTYPE OF (IfcControl);
  PredefinedType : OPTIONAL IfcCostItemTypeEnum;
  CostValues : OPTIONAL LIST [1:?] OF IfcStrippedOptional;
  CostQuantities : OPTIONAL LIST [1:?] OF IfcStrippedOptional;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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