It was somewhere outside Barstow when WillR
wrote:

IMHO - each job gets assigned overhead.

You can't assign overheads - that's the point, they're the bit that's
not assignable, because you either have to pay it anyway (rent) or you
can't track where it went (who finished the sandpaper?). Your jobs
have to be sufficiently profitable in total to allow you to pay for
overheads out of the general budget. Not assigning them doesn't mean
that you have to run at a loss.