How can we make fields non-editable in Production Order change transactions?
As far as I checked, one cannot make fields non-editable in the Production order.
Reference - Make Quantity field non-editable in goods movement screen in Confirm Production Order Operation (https://answers.sap.com/questions/13797265/make-quantity-field-non-editable-in-goods-movement.html)
Also I checked in the custom logics (Business Add-Ins) and could not find anything either - https://help.sap.com/docs/SAP_S4HANA_CLOUD/2bba750d1e124e1ea2a039bb1cd9b6c5/c20b8cfa8000468d86a005ec...
Furthermore there is already an improvement request & you can vote it here - Material / Component list should be non editable in Process/Production order (might not be fully matching your requirement, but still this might help as you can add your comments too) - https://influence.sap.com/sap/ino/#/idea/312534/?section=sectionDetails