Don't establish a system. They should work because they have a job and are getting paid to do that job. Be the boss and put your foot down and tell them that these callbacks are unacceptable and start giving them days off when you get call backs... Joe was trimming on that route that day and a callback was about trimming being missed....Joe gets a day off the next week...... that being said, the first week there are no callbacks have a McDonald's breakfast on Monday morning.......BUT be clear it is a thanks for listening to you.........the boss and is not to be expected every week. I don't understand bonuses for doing the job you are hired to do. Bonuses are for going above and beyond and finding ways to save the company money. Such as a guy sees a simple way to improve the route. It saves you an hour a day so by the end of the week it saves you 5 hours a week which equates to, let's say $2 to 300 a week....you give the guy that pointed that out ( not the entire crew) an extra $50 for saving you hundreds. You don't reward people for doing what they are supposed to do. If you are hired to cut grass and edge and trim and blow, what I pay you dictates that job. If I pay the guy 10 an hour to mow, trim and blow, then he gets paid 10 bucks an hour. The guy doesn't get an extra something something for doing his job. He's already taking 10 bucks an hour out of your pocket to do the job he is supposed to do...why give him more money out of your pocket to do the job you're already paying him for? It makes no sense. He does his job well or he doesn't do it at all. If you're going to give them a bonus for doing their job, then you might as well pay them that per hour and raise your hourly rate.