Hi,I think you don't need to create PV because PV you have to assign to the Material in MRP4 view and from there it picks up automaticallyYou can go for Order splittinghttps://help.sap.com/docs/SAP_S4HANA_ON-PREMISE/34de0103497c4b80a7c7fbf6952ff971/9...

hope this helpshttps://help.sap.com/docs/SAP_CLOUD_FOR_CUSTOMER/24765b551a014b779b95c7b07d8e9079/4b49af367a29482aa60ce66ca624e8a2.html?locale=en-US

MPN is to be set up as MPN profile in SPRO under MM-> Purchasing--> define MPN profile.Try to use MPN profile and also set MPN indicator in customizing and then try in MM01In Customizing for the Material master, the indicator Manufacturer part number...