The job responsibility is exactly the same in the department.
The department has a total number of working hours required. The total retention is about 50% a year, and the hiring cost is about $2000 per person.
Salary is about $12 per hour. Full time works 40 hours, while part time works 20 hours per week.
Is this an optimization or simulation problem? I guess the output is a range of workers required. How to model this?