Hotel personnel scheduling problem

A simple calculation: a ***7 people, if each of these 7 people can get the qualification of ABCH class, it will be easy to arrange! Take six days off per person/month, with an average of 1 time, and take about five days off; At least four or five people can go to work every day, and the remaining three or two people can arrange rest (or arrange to be in class D). Of course, you can avoid Saturday and Sunday and only arrange Monday to Friday (or avoid Friday and Saturday and only arrange Sunday to Thursday)! ! ! Besides, there are only seven people. Maybe the hotel is not very big. Under the premise of not affecting work at all, employees can arrange their own rest days (avoiding weekends), which is more humane! Small suggestion, for reference only! Ha ha!