How To Fix MM129 - The base unit of measure is not the smallest unit of measure

SAP Error Message - Details

• Message type: E = Error

• Message class: MM - Messages for material master maintenance and Customizing

• Message number: 129

• Message text: The base unit of measure is not the smallest unit of measure

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message MM129 - The base unit of measure is not the smallest unit of measure ?

  The SAP error message MM129, "The base unit of measure is not the smallest unit of measure," typically occurs in the Materials Management (MM) module when there is a discrepancy between the base unit of measure (UoM) defined for a material and the other units of measure that are defined for that material.
  Cause:
  
  Incorrect Configuration: The base unit of measure is not set correctly in the material master data. The base unit of measure should always be the smallest unit of measure for that material.
  Multiple Units of Measure: If you have defined multiple units of measure for a material, the base unit must be the smallest one. For example, if you have a base unit of measure as "KG" and you also have "G" defined, then "G" should be the base unit of measure instead.
  Unit of Measure Conversion: There may be issues with the conversion factors defined between the base unit of measure and other units of measure.
  
  Solution:
  
  
  Check Material Master Data:
  
  Go to the material master record (transaction code MM02).
  Check the "Basic Data" view and ensure that the base unit of measure is indeed the smallest unit of measure.
  If necessary, change the base unit of measure to the correct smallest unit.
  
  
  
  Review Units of Measure:
  
  In the "Units of Measure" view of the material master, verify that the conversion factors are correctly defined.
  Ensure that the base unit of measure is the smallest unit in the list of units of measure.
  
  
  
  Adjust Conversion Factors:
  
  If you have defined conversion factors, ensure they are correct. For example, if 1 KG = 1000 G, then the conversion factor should reflect that accurately.
  
  
  
  Consult Documentation:
  
  If you are unsure about the correct units of measure for your materials, consult your organization's documentation or guidelines regarding unit of measure definitions.
  
  
  
  Testing:
  
  After making changes, test the material by trying to perform the action that previously resulted in the error to ensure that the issue is resolved.
  
  
  
  Related Information:
  
  Transaction Codes: 
  
  MM01 - Create Material
  MM02 - Change Material
  MM03 - Display Material
  
  
  Unit of Measure Configuration: You can also check the configuration settings for units of measure in the SAP system via the SPRO transaction (Customizing).
  SAP Notes: Check SAP Notes for any specific patches or updates related to this error message, as there may be known issues or additional guidance provided by SAP.
  
  By following these steps, you should be able to resolve the MM129 error and ensure that your material master data is correctly configured.