How To Fix CN023 - You cannot delete. Activity "&" has been replaced by a subnetwork

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 023

• Message text: You cannot delete. Activity "&" has been replaced by a subnetwork

What causes this issue?

Activity &V1& in the network has been replaced by a subnetwork. You
cannot delete the activity.

System Response

INCLUDE 'NA_ALLG_NOFUNKTION' OBJECT DOKU ID TX
To delete the activity, you must first delete the subnetwork
activities.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN023 - You cannot delete. Activity "&" has been replaced by a subnetwork ?

  The SAP error message CN023 indicates that you are trying to delete an activity in a project that has been replaced by a subnetwork. This typically occurs in the context of project management within SAP, particularly when using the Project System (PS) module.
  Cause:
  The error occurs because:
  
  The activity you are attempting to delete has been replaced by a subnetwork. In SAP Project System, a subnetwork is a grouping of activities that can be managed as a single entity. When a subnetwork is created, it takes over the management of the activities that were previously part of the main network.
  The system prevents the deletion of the original activity to maintain data integrity and ensure that the relationships and dependencies within the project structure are preserved.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check the Subnetwork: Verify if the activity you are trying to delete is indeed part of a subnetwork. You can do this by checking the project structure in the Project Builder (transaction code: CJ20N) or the Network Overview (transaction code: CN03).
  
  
  Delete the Subnetwork: If the subnetwork is no longer needed, you may consider deleting the entire subnetwork. This will allow you to delete the original activity. However, be cautious as this may affect other parts of your project.
  
  
  Adjust the Project Structure: If you need to keep the subnetwork, consider adjusting the project structure instead of deleting the activity. You may want to modify the subnetwork or its activities as needed.
  
  
  Consult Documentation: Review the SAP documentation or help files related to Project System and subnetworks for more detailed guidance on managing project structures.
  
  
  Seek Help from SAP Support: If you are unsure about the implications of deleting a subnetwork or if you encounter further issues, consider reaching out to your SAP support team or consulting SAP Notes for specific guidance related to your version of SAP.
  
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as CJ20N (Project Builder), CN03 (Network Overview), and CN21 (Create Network).
  SAP Notes: Check for any SAP Notes that may address this specific error or provide additional context.
  Project Management Best Practices: Understanding best practices in project management within SAP can help prevent similar issues in the future.
  
  By following these steps, you should be able to address the CN023 error and manage your project activities effectively.