Here you determine if you want the procedures Loading Selection in the Manufacturing module or Requirement Calculation in the Inventory module – or both – to be opened automatically when you save the order. If so, these procedures will create a calculation based on the data they receive from the manufacturing order. By default, neither of these procedures will start automatically when you save the order.
The purpose of "AutoStarting" these procedures is to be able to see in the Requirement Calculation procedure whether you have any material shortages for this order. Or to use the Loading Selection procedure to see whether this order will create any overload warnings for any of the work centers.
In order to get warnings if overloading is created for work centers, you must make sure that the work centers are set to Bottleneck.