How To Fix O3020 - UoM group & assigned to a material; not possible to change or delete

SAP Error Message - Details

• Message type: E = Error

• Message class: O3 - IS-Oil: HPM messages (goods movements, QCI, deliveries)

• Message number: 020

• Message text: UoM group & assigned to a material; not possible to change or delete

What causes this issue?

The unit of measure group has already been assigned to a material and
therefore cannot be modified or deleted.

How to fix this error?

Once stock is posted to a material, you cannot change the unit of
measure group for the material. The unit of measure group has to be
identical for all plants of a given material. For additional
information, read SAP note 145824.
It is recommended to use the UOM group enhancement report
?R_OIB_01_UOM_ADD_INSERT_SUM? to add a new UOM. Please, refer to OSS
Note 2328459 for usage & implementation
If any other methods are used, it can create severe inconsistency in the
database tables.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message O3020 - UoM group & assigned to a material; not possible to change or delete ?

  The SAP error message O3020 indicates that there is an issue with the Unit of Measure (UoM) group assigned to a material. Specifically, it means that the UoM group is currently in use and cannot be changed or deleted. This can occur in various scenarios, such as when the UoM group is linked to existing transactions, materials, or other master data.
  Cause:
  
  Active Transactions: The UoM group is being used in active transactions, such as purchase orders, sales orders, or inventory records.
  Material Master Data: The UoM group is assigned to a material that is currently in use or has historical data associated with it.
  Dependencies: There may be dependencies on the UoM group in other areas of the system, such as pricing, inventory management, or production planning.
  
  Solution:
  
  Check Active Transactions: Review any active transactions that may be using the UoM group. You can do this by checking purchase orders, sales orders, or any other relevant documents.
  Change UoM Group: If you need to change the UoM group, ensure that there are no active transactions using it. You may need to complete or delete these transactions first.
  Material Master Maintenance: If you need to delete or change the UoM group in the material master, ensure that the material is not in use. You can check the material's status and usage in various transactions.
  Consult with Users: If you are unsure about the transactions or dependencies, consult with users or departments that may be using the UoM group to understand its current usage.
  Use Transaction Codes: Utilize transaction codes like MM02 (Change Material) or MM03 (Display Material) to check the material master data and UoM group assignments.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as MM01 (Create Material), MM02 (Change Material), and MM03 (Display Material) for managing material master data.
  SAP Notes: Check SAP Notes for any specific issues or updates related to UoM groups and error O3020.
  Documentation: Review SAP documentation or help files related to material management and unit of measure handling for best practices and guidelines.
  
  If the issue persists after following these steps, it may be necessary to involve your SAP support team or consult with SAP experts for further assistance.