Create SFC 
You use the DM520 hook point activity to create the SFC number the first time it is seen by the system. This avoids the need to release demand before materials can be produced on the shop floor.
This hook point activity is commonly used with automatic equipment such as barcode scanners that work with automated machines.
Valid hook points for Create SFC are PRE_VALIDATE_START and PRE_START at the operation or resource level.
You have set up a resource with Material or Shop Order type in Resource Setup (see Resource Setup).
If used together with Check Next Number (EN520), you have to set up EN520 to run before Create SFC at the same hook point (either PRE_START or PRE_VALIDATE_START).