Cannot change Valuation Class although no Open-PO

Question

Dear Gurus,
I try to change Valuation Class in Material Master but I cannot after I created PO and still after MIGO and MIRO.
We are using PS and Material Master is set as below;
Ind./Coll in MPR4 = 1
Since requirement comes from PS, PO is created with account assignment category Q.
Once we execute MIGO and MIRO for the PO, still we cannot change Valuation Class.
If you know the way to change Valuation Class, would you tell me how?
Best Regards,
AK

Answer 1

Hi,
The change of the valuation class will impact on ML (material ledger), if the ML
is active. Is ML active on your system?
The note 575632 explains partly the effects on CCS. The
valuation class is used to allocate the plan costs to the related cost
element. Therefore, it is advisable to create new materials instead of
changing the valuation class. This would be straight forward and easy to
follow-up. The CCS does not a change history. Consequently, the previous
periods can not be explained with current CCS. That may lead
inconsistencies under circumtances. It is up to your decision. You can
change, test the impact and decide on. The proposed solution of SAP
would be avoiding that change and creating new materials.
When you try to change the valuation class, what is the details of the
error?
In order to change valuation class in the material master, you have to
make sure that none of the following exist in you system:
1  Valuated stocks in the current period or in the previous period
2  Open purchase orders or delivery schedule lines
3  Production orders for which a goods movement has already taken place
The system checks the stocks (storage loc. stocks and special
stocks) of the same period in which the valuation class will be changed.
If the valuation class of current period will changed, check in
transaction code MMBE for zero stocks, or in SE16: MARD/MBEW;
MCHB/MKOL/MSKA/MSKU/MSLB/MSPR.
The system checks all dependant purchase documents without delete flag
and error M3368 occurs when it finds at least one non deleted po item
(not only when stocks exist).
1. First be sure that no stocks exist in current AND previous period!
   see note 30656, with an example how to get zero stocks.
2. SE16 ->table EKPO. Select all po items of the related material.
   If you found items with LOEKZ <> 'L', you have to delete them in ME22
3. SE16 ->table AFPO. Select all items of the related material/plant.
   If you find at least one item, change of val.clss. is not possible.
   You have to these production order(s) !
These hard restrictions are necessary as inconsistencies in account
assignment will follow after change of val.class, when proceeding
follow up functions of a PO item before and after changing valuation
class. Also attached is 146241.
In customizing for the Material Master, you can switch the check for
open purchase orders and/or for production orders to a warning.
You do this in Define Attributes of System Messages by assigning
the message type Warning to message MM 326 and/or MM 327 respectively.
Please refer to note 160970 for more information.
I hope this will help you in resolving the reported issue.
Best Regards,
Arminda Jack