How To Fix BM311 - Units of different dimensions cannot be converted

SAP Error Message - Details

• Message type: E = Error

• Message class: BM - Development class BZME - units of measure

• Message number: 311

• Message text: Units of different dimensions cannot be converted

What causes this issue?

The units of measure involved have different dimensions. Conversion
from one unit to another is therefore not possible.

System Response

Conversion cannot be performed.

How to fix this error?

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 BM311 - Units of different dimensions cannot be converted ?

  The SAP error message BM311, which states "Units of different dimensions cannot be converted," typically occurs when there is an attempt to convert or process quantities that have incompatible units of measure. This can happen in various contexts, such as during material movements, inventory management, or when working with bills of materials (BOMs).
  Cause:
  
  Incompatible Units: The most common cause is that the units of measure being used are not compatible. For example, trying to convert between mass (kilograms) and volume (liters) without a defined relationship (like density).
  Incorrect Configuration: The units of measure may not be correctly defined in the system, or the conversion factors may be missing or incorrect.
  Data Entry Errors: Manual entry of units may lead to inconsistencies, such as entering a unit that does not match the expected dimension.
  Material Master Issues: The material master data may have incorrect or missing unit of measure settings.
  
  Solution:
  
  Check Units of Measure: Verify that the units of measure being used are compatible. Ensure that you are not trying to convert between fundamentally different dimensions (e.g., mass to volume).
  Review Material Master Data: Go to the material master record and check the units of measure defined for the material. Ensure that the base unit of measure and any alternative units are correctly set up.
  Define Conversion Factors: If applicable, ensure that conversion factors between different units of measure are defined in the system. This can be done in the configuration settings for units of measure.
  Correct Data Entry: If the error is due to manual data entry, correct the entries to ensure that the units of measure are consistent and valid.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on the context in which the error occurred (e.g., during a specific transaction or process).
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes like MM02 (Change Material), MM03 (Display Material), or OME4 (Define Units of Measure) to check and modify unit settings.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  User Exits and BAdIs: If you are using custom developments, check if there are any user exits or BAdIs that might be affecting unit conversions.
  
  By following these steps, you should be able to identify the cause of the BM311 error and implement a solution to resolve it.