Physical quantities and numbers

Hi
I would like to share an experience and give remarks about physical quantities.
I use “physical quantities” type to describe physical quantities, and number to describe their measures or operations when some are related:
Physical quantities are related to units, to me unit is a reference value created to enable measuring, so what should relate physical quantity is not the unit (metre) but the dimension (length). At least, the multiplier could be different between literal values.
But when I have to describe measure, I have no relation to unit, and there I would like to use not only main unit but full unit-unit and multiplier (millimetre), as only the number is in the value.
Now comes a mismatch: Physical quantity has no literal value dedicated, then I use numerical, but this creates unit consistancy issues when validating…
What I have one in my model:
I built a complex set of property values and groups that applies to exhange items, classes and types, this to set the different exchange natures : Material (which); energy (which) information, and related dimensions. My aim was to track consistancy between exchange mechanism; exchange item nature, element nature, and typing class or type nature; then between EI nature and physical link (but then I have to cross conveying FEs and CEs). My current try is to use categories for FE; CE and PL, but keeping in mind it would be an alternative to set PVG as well. The check works with a big Excel file fed by csv exports by data table import, and then query management. I take alerts there to check my model. My model have solid mechanics, electrical power, material exchange, fluid operations & feed back, electrical operations & feed back, user handle actions, displays, view field, analog infos related and digital data… that measures and operates all this.

I understand that changing the role in the application of the unit could be a big change, but still if there are some chances…
Thanks for the patience of reading me till the end.
Thierry Poupon