ifcreassignstogroupbyfactor的对象化关系是一般分组机制的特化。它允许添加一个因子来定义应用于将对象定义（单个对象引用作为IfcObject的子类型，对象类型作为IfcTypeObject的子类型）分配给组（IfcGroup的子类型）的比率。
比率可用于定义百分比分配。例如，系数0.8表示对象被80%分配给组，系数2.5表示对象被分配给组的权重系数为2.5。
注：系数组的示例包括结构分析中荷载组合中的荷载工况分配，或按百分比将空间分配给不同的租赁区域。
对于许多组，同一对象或对象类型可能包含相同或不同的因子值。分组关系不是分层的。
在IFC4中增加的新实体。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| IfcRoot | |||||
| 1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X |
| 2 | OwnerHistory | IfcOwnerHistory | [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 |
| 3 | Name | IfcLabel | [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 |
| 4 | Description | IfcText | [0:1] | Optional description, provided for exchanging informative comments. | X |
| IfcRelationship | |||||
| IfcRelAssigns | |||||
| 5 | RelatedObjects | IfcObjectDefinition | S[1:?] | Related objects, which are assigned to a single object. The type of the single (or relating) object is defined in the subtypes of IfcRelAssigns. | X |
| 6 | RelatedObjectsType | IfcObjectTypeEnum | [0:1] | Particular type of the assignment relationship. It can constrain the applicable object types, used within the role of RelatedObjects. | X |
| IfcRelAssignsToGroup | |||||
| 7 | RelatingGroup | IfcGroup | [1:1] | 对包含所有分配的组成员的组的引用。 | X |
| IfcRelAssignsToGroupByFactor | |||||
| 8 | Factor | IfcRatioMeasure | [1:1] | 作为比率度量提供的因子，用于标识应用于组分配的分数或加权因子。 | X |