Hey. Yes, this problem often occurs. I think you need to control the computers of your employees. For example, SoftActivity will help to track the programs used by employees, their Internet history. But do not forget that they also need rest. It would be nice if you have a seating area where they can relax. Studies have shown that if you give a person a rest after each hour of work, then his productivity does not decrease, than if you do not give rest at all or just for lunch.