How are Element and Attributes Identified as Upgrade Candidates?

In Schematic Model Manager 12.0 SP6 an Attribute Mapping could have an Attribute Type. This was then used with the Source Attribute Units to set the value during import.

The Attribute Mappings for the project will be used to generate a list of attributes (UDAs and Core) that had an Attribute Type associated with them. For each of these attributes the unit that was used for the value during import will be determined using the units UDAs (Pmguntsangle, Pmguntsarea, Pmguntsdist, Pmguntpres, Pmguntstemp, Pmguntvolm, Pmguntweig), the project options units and the value of :pmgmodtime (time of import). In 12.1 units are managed centrally in the application and so there are units specified for all of the possible Attribute Types. Any attribute on an element which was imported using a different unit to this centrally managed unit will be reported as an upgrade candidate.