IfcConstructionProductResource limitation use case in Cost Norms/ Resource Built-up

When trying to assign an [7.3.3.5 IfcConstructionProductResource - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcConstructionProductResource.htm) that as it is defined in the schema defines the role of a product that is consumed (**_wholly or partially_**), or occupied in the performance of construction, we have the following :


the [8.17.3.5 IfcQuantityCount - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcQuantityCount.htm)


and [8.11.2.12 IfcCountMeasure - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCountMeasure.htm)


but, in all norms that use a combination of resources the "number of pieces" used of a product that is part of a resource schedule item (resource build-up/ recipe/ cost article) is in most cases a fragment of a whole to correspond to the general unit of measurement of the recipe.


You could say that there is a "work around" and use the [7.3.3.3 IfcConstructionMaterialResource - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcConstructionMaterialResource.htm) which means that I have to set a "pcs Unit" = in order to use the [8.17.3.7 IfcQuantityNumber - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcQuantityNumber.htm) in order to use a
[8.11.2.65 IfcNumericMeasure - IFC 4.3.2 Documentation](https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcNumericMeasure.htm). If so which one of the IfcContextDependUnit do we have to use to describe an IfcQuantityNumber?

picture from BONSAI Unit Declaration