How To Fix MD421 - &1: &2 &3 (U3)

SAP Error Message - Details

• Message type: E = Error

• Message class: MD - Material Requirements Planning (MRP)

• Message number: 421

• Message text: &1: &2 &3 (U3)

What causes this issue?

There is no requirements for this receipt. It should be reversed to
avoid unnecessary warehouse stock.

System Response

This exception is displayed in the MRP list, and in the
stock/requirements list.

How to fix this error?

Check whether the receipt can be reversed.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message MD421 - &1: &2 &3 (U3) ?

  The SAP error message MD421 typically relates to issues in the Material Requirements Planning (MRP) process, specifically when there are problems with the availability of materials or the planning of production orders. The message format you provided indicates that it is a warning or error related to the MRP run.
  Cause:
  The error message MD421 usually indicates that there is a problem with the availability of materials for a specific production order or planned order. The placeholders &1, &2, and &3 in the message represent specific details about the error, such as:
  
  &1: The material number
  &2: The plant or location
  &3: Additional information or context about the error
  
  Common causes for this error include:
  
  Insufficient stock of the material.
  Incorrect planning parameters.
  Issues with the bill of materials (BOM) or routing.
  MRP settings that do not align with the production requirements.
  
  Solution:
  To resolve the MD421 error, you can take the following steps:
  
  
  Check Material Availability: Verify the stock levels of the material in question. Use transaction codes like MMBE to check stock levels and availability.
  
  
  Review MRP Settings: Ensure that the MRP parameters for the material are correctly set. This includes checking the lot size, safety stock, and reorder point settings.
  
  
  Examine BOM and Routing: Check the bill of materials and routing for the production order. Ensure that all components are correctly defined and available.
  
  
  Run MRP Again: After making any necessary adjustments, run the MRP process again to see if the issue is resolved. You can use transaction code MD02 for single-item planning or MD01 for total planning.
  
  
  Check for Errors in MRP Run: Review the MRP run logs for any additional errors or warnings that may provide more context about the issue.
  
  
  Consult Documentation: If the issue persists, refer to SAP documentation or consult with your SAP support team for further assistance.
  
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as MD04 (Stock/Requirements List), MD05 (Individual Display of MRP List), and MD06 (Collective Display of MRP List).
  SAP Notes: Check SAP Notes for any known issues or patches related to the MD421 error.
  User Forums: Engage with SAP community forums or user groups for insights from other users who may have encountered similar issues.
  
  By following these steps, you should be able to identify and resolve the underlying cause of the MD421 error in your SAP system.