How To Fix /SAPAPO/AHT428 - Action &2 for event &1 is locked by a parallel work process

SAP Error Message - Details

• Message type: E = Error

• Message class: /SAPAPO/AHT -

• Message number: 428

• Message text: Action &2 for event &1 is locked by a parallel work process

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message /SAPAPO/AHT428 - Action &2 for event &1 is locked by a parallel work process ?

  The SAP error message /SAPAPO/AHT428 Action &2 for event &1 is locked by a parallel work process typically occurs in the SAP Advanced Planning and Optimization (APO) module when a specific action or event is being processed by another work process. This locking mechanism is in place to prevent data inconsistencies that could arise from concurrent processing of the same event.
  Cause:
  
  Concurrent Processing: The most common cause of this error is that the event or action you are trying to execute is already being processed by another user or work process. SAP uses locks to ensure that only one process can modify a particular piece of data at a time.
  Long-Running Processes: If a process takes a long time to complete, it can lead to other processes being blocked, resulting in this error.
  System Configuration: In some cases, the system configuration or settings related to parallel processing might lead to locking issues.
  
  Solution:
  
  Wait and Retry: The simplest solution is to wait for a few moments and then retry the action. If the other process completes, the lock will be released, and you can proceed.
  Identify the Lock: Use transaction code SM12 to check for locks in the system. You can look for the specific event or action that is locked and identify the user or process holding the lock.
  Terminate the Lock: If you find that a process is stuck or taking too long, you may need to terminate it. This should be done with caution and typically requires appropriate authorizations.
  Review Process Design: If this error occurs frequently, consider reviewing the design of your processes to minimize the chances of concurrent processing on the same events.
  Increase System Resources: If the issue is related to long-running processes, consider optimizing the performance of your system or increasing the resources available to it.
  
  Related Information:
  
  Transaction Codes: 
  
  SM12: To view and manage locks.
  SM21: To check system logs for any related errors or warnings.
  ST22: To check for dumps that might provide more context on the issue.
  
  
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  Documentation: Review the SAP APO documentation for best practices on managing events and actions to avoid locking issues.
  
  If the problem persists after trying the above solutions, it may be beneficial to consult with your SAP Basis team or SAP support for further assistance.