Use
When you create an order or schedule a master recipe, you use the scheduling type to determine the following:
Prerequisites
The required scheduling types have been defined in Customizing for Process Orders.
Features
The following scheduling types are available:

When you schedule process orders, the system determines capacity requirements at the phase level and secondary resource level. This is why this type is called Only capacity requirements.
You also use the scheduling type to determine whether a date, or a date and a time is required for the basic dates.