Workload Scheme: allows admin user to create schemes and add them later to the users (employees). For example part time scheme, full time scheme. Main reason being; business hours do not necessarily reflect the workload for a particular person, i.e. my company can be open 24/7 it doesn't mean my employees work that amount of time. 

Holidays Scheme: companies working in different countries need different schemes, so they can be related to specific employees. For example I'd create a Holiday Scheme for the US, another for Costa Rica, etc.