Clarification required on how an IfcTask consumes IfcResources

IfcTask has this definition:

> Quantities of resources consumed by the task are dealt with by defining the IfcElementQuantity for the resource and not at the instance of IfcTask.

This is confusing, since there are at least three locations I can think of to define a quantity:

1. IfcConstructionResource.BaseQuantity (note: it's a IfcPhysicalQuantity, not an IfcElementQuantity)
2. IfcRelAssignsToProcess.QuantityInProcess (note: it's a IfcMeasureWithUnit, not an IfcElementQuantity)
3. IfcConstructionResource.IsDefinedBy.RelatingPropertyDefinition (note: this is an IfcElementQuantity, but no Qtos are defined, nor is it described in any general concepts for IfcConstructionResource).

Which is the correct location? What is the purpose of IfcRelAssignsToProcess.QuantityInProcess? Does IfcRelAssignsToProcess.QuantityInProcess override IfcConstructionResource.BaseQuantity? Is "BaseQuantity" a unit quantity? If it is a unit, does it need to be multiplied by something to get the final usage?

Here is an example diagram of the first two locations with conflicting data to describe the sentence "10m3 of concrete is consumed by a task":


Ping @TLiebich @sigmadimensions