"Completely misunderstood" would have been far more efficient.
If you base it on such terms, their time can easily appear to be valued much less some hourly employees. How are you supposed to log the hours when the various processes are so varied and often sporadic? Does every minute slightly related to work count towards hours worked? Even a salaried employee who has a eureka moment in a dream, and then gets to organizing his thoughts in the middle of the night can't put that on his time card.
Nevertheless, you insist on condensing their compensation to the most basic of units, which is largely inapplicable because they are not paid in those units.
I still maintain that, after all is said and done, they're wasting their time building basses if they end up with six bucks an hour for their efforts. There has to be some level of efficiency. I was salaried for most of my career, but I still filled out a time sheet, even when I was the boss.
As for the variable and sporadic tasks, a simple system of activity codes could be used for things like laminating, rough cutting, shaping, neck shaping, fretting, etc. I would want to know how much time was being spent on each aspect so I could figure out ways to make each process more efficient.
