Payroll Does not Measure Productivity
Today I found an article by Norman Badger who is a senior VP for Publix, a chain of grocery and retail stores in the southeastern US.
Beyond the Clock: Measuring Productivity Beyond Hours Worked.
In a nutshell, Norman points out why time-based productivity falls short. For example, measuring productivity is more about "quality, results, and balance". He mentions "leaders and employees are learning that actual productivity is not about time - it's about value."
I think Norman is right, time does not measure productivity.
But unfortunately that thought does not align with payroll. For the most part, employees are not paid for productivity, they are paid for the hours worked. That is unless they are a tip worker, commission only, or are paid per piece.
Time is very easy to measure, just use a time clock.
Productivity is not easy to measure and never has been, it comes with ebbs and flows. It's more about consistently managing a team to do their best.
You could however offer performance bonuses.
Pay folks more if they are more productive... You just have to figure out a way to measure it.