About Process Steps
Process steps describe all the actions used to manufacture the product. You can only have one active step at any time. Process step types are: Fixture, Manufacturing Model, Machine, General, Surface, and Volume. You must create a Work Center before creating the process step. Every process step type is associated with a specific work center type. For example, a Work Center of type Surface enables you to create a Surface type step.
You can create a work center at setup time and then use it in an operation, or create a work center directly when defining an operation. To create a Work Center, click Manufacturing and the arrow next to 
Work Center. Select a type of Work Center or machine tool from the list. The Work Center dialog box for the selected type opens.
Work Center. Select a type of Work Center or machine tool from the list. The Work Center dialog box for the selected type opens.