Per Kim you should use resources:
As a rule of thumb, Resources are meant to represent labor and overheads. Resources have a Unit Rate expressed in time (eg: $/Minutes or $/Hours) and adds an indirect cost as a % of the rate (ie: An overhead).
Resources are intended for use in Assembly BOM.
You can also run a high level capacity overview using them. IE: You can say "Drill Press" is available for 40 hours a week, and run a view that shows your assemblies scheduled in a week needed 55 hours of your 40 hours. It's not exact because if you have an assembly that starts on Friday at 3 pm and need 10 hours of Drill Press, obviously it'll happen on Monday - but Assemblies aren't sophisticated enough to handle that.
Hope that helps!
-Rob
(PS: I have a thought that a Power App could be used to collect "actuals" from staff and then push that back into the assembly before posting it. We might work on that as it would make Assemblies more useful).
