How many plumbers should the property management company 1500 households have?

Generally, there are four maintenance personnel, and the team can go to work in four shifts and three shifts, that is, each person has three days off 1 day, and there are three people a day (two during the day, night shift 1), and the same is true for water and electricity.

Among them, the night shift electrician can be on duty in the high-voltage distribution room, which also saves the high-voltage duty personnel.