I tried with the Sourcing option - Use Sourcing rule and with the sourcing rule defined for Shop order. But, as soon as we enter a new sales part number that triggers validation, it causes a change in the entered sourcing option. The value will remain if we can enter the sourcing option after that validation triggering action. 

Piyal Perera, thank you for the response.  So, if I understand you correctly, there is no way to update this Sourcing Option to default to a different value so that it automatically defaults to this other value.  Is that correct?

@evanspa3 in 23R1 SU4 when I try to create the sales part and choose Shop Order as Sourcing Option, the options stays and doesn’t get changed to Inventory Order.

After saving:

Changing the default value is not configurable. Normally, most screens have a function called Get_Defaults → and inside the function these values are hardcoded → so you would need a small modification of the get_defaults function if you want the default value of the sourcing option to change to Shop Order instead of Inventory Order.

Yes. No direct solution. But, there are two options if possible:

1. The value will remain if we can enter the sourcing option after that validation triggering action. So, we can enter generated part no first, then enter sourcing option.
2. As Marcel explained above