Field Selection Group Mapping OMSR - discrepancies between SAP ECC and S/4HANA

[yschlaeppi]

Dear SAP Community, 

I am doing a brownfield transition and realized on the material master some changes in mapping to Field Selection Group (FSG). For example MARC-KAUTB Indicator automatic purchase order allowed is in ECC in FSG 16, new in S/4H it is in FSG 52. Of course we can re-assign to FSG 16, however if we do so, we get notified that we can only change in custom name range (does not make sense, there is no custom range for Field sel.group...). If we proceed with re-assignment back to the FSG we used to have in SAP ECC, what happens with a patch/release change in S/4HANA. Is an upgrade overwriting our Field Selection Group assignments or are these settings excluded with an upgrade -- this the key question we need answered beforehand. If so, we would need a step in the patch/upgrade routine to reprocess the mapping of the FSG. 

Thank you to provide insight as soon as possible.

#S/4HANA Logistics

[yschlaeppi]

I have checked now also the tables T130A and T130F, both have Delivery Class E assigned. Delivery class E System table in which customers can make entries. A system table in the delivery class E must be assigned a customer namespace in the database table TRESC using the program RDDKOR54. •These system tables are delivered with prefilled entries. •In client copies, the data of client-dependent tables is copied. Any client-independent data is not copied. •In installations, updates, and language imports, all data is imported, and existing data is overwritten. •In transports between customer systems, all data is transported. In client-dependent tables, only the data in the specified target client is respected. •Any data entered using extended table maintenance (transaction code SM30) is checked here for any violations of the namespace assigned in the DDIC database table TRESC. Do I need to reassign the Table Delivery Class from E to C to protect Field Status Group assignments from future upgrade setbacks? Thank you to confirm/advise to this inqury.