Tie pay to performance then. As for Fridays, start a baserate bidding market for your workers and the lowest asks win the given shift. If pay for the shift scales with number of plates served (without tips) AND Fridays pay more because the lowest ask on Fridays is typically higher than on other days, then it should not be much different than now except your customers don't feel mugged. Just ban customer tipping!
Probably best to tie this all together in a "Lowest listed price is final price" law that includes a hotline for customers to report businesses/staff who retaliate over no tipping. Mainly it's so the agency can send secret shoppers of their own to test for social retaliations/pressure.
You could devise some contraption ("baserate bidding market") that is +/- 5% more {fair, transparent, predictable} than tipping, in the same way that you could improve or degrade sales compensation by eliminating commissions, yes.
Probably best to tie this all together in a "Lowest listed price is final price" law that includes a hotline for customers to report businesses/staff who retaliate over no tipping. Mainly it's so the agency can send secret shoppers of their own to test for social retaliations/pressure.