I like the idea, but a lot of other factors are missing from the analysis. 1. I’ve yet to find a service that saves 5 hours per week per employee. How do I estimate the actual savings in time? 2. Work expands to fill available time. Will my employee use that time to the company’s advantage? 3. How much does this increase or decrease my personal time required as supervisor? 4. From a financial point of view, I’m still…
Take a management class or three, it'll save you a lot of money.
Seriously. If that needs to figure into the evaluation of the service, something is deeply broken in the culture of your company. Not because employees goof off - it happens, and only some amount of that is under your control. But because you assume that given any chance, people would goof off more.
That's far from normal. It usually happens if employees feel mistreated, or if they're not given a fair share of the value they create. Possibly if they're already halfway to leaving.