If you have activated the setting Use staffing factor exceptions for operations?, under Preparations under the Manufacturing tab in the Settings procedure, you will see the Staffing factor column on operation rows. Here you can enter staffing factor exceptions on operations in a preparation. The staffing factor entered here will override the staffing factor entered on the work center in the Update Work Center procedure and that is shown in the Staffing factor WC on the operation row.
If you use cost factor exceptions, which is activated by the setting Use cost factor exceptions? under Work Centers under the Manufacturing tab in the Settings procedure, the fields Cost factor exception and Staffing factor will be highlighted in yellow when a value is selected. Nothing will be highlighted in yellow if you also select a cost factor exception. The purpose of the fields highlighted in yellow is to indicate that two selections are to be performed to affect both the calculation and loading. It is reasonable to select a cost factor exception if another staffing than the regular is used since it will affect the calculation.