How To Fix CN520 - External Network Activity cannot be selected for network scheduling

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 520

• Message text: External Network Activity cannot be selected for network scheduling

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message CN520 - External Network Activity cannot be selected for network scheduling ?

  The SAP error message CN520 ("External Network Activity cannot be selected for network scheduling") typically occurs in the context of project management and network scheduling within SAP's Project System (PS) module. This error indicates that the system is unable to schedule an external network activity, which is often due to the nature of the activity or its configuration.
  Cause:
  
  
  External Activity Type: The activity in question is marked as an external activity, which means it is not intended to be scheduled within the internal network of the project. External activities are usually linked to external resources or vendors and are not part of the internal scheduling process.
  
  
  Network Configuration: The network might be configured in such a way that it does not allow for external activities to be included in the scheduling process.
  
  
  Dependencies: There may be dependencies or constraints that prevent the scheduling of the external activity within the current network.
  
  
  Status of the Activity: The status of the external activity may not allow it to be scheduled (e.g., it might be marked as completed or inactive).
  
  
  Solution:
  
  
  Review Activity Type: Check the type of the activity in question. If it is indeed an external activity, consider whether it should be included in the internal scheduling or if it should be managed separately.
  
  
  Adjust Network Settings: If you need to include the external activity in the scheduling, you may need to adjust the network settings or configuration to allow for this. This might involve changing the activity type or modifying the network structure.
  
  
  Check Dependencies: Review any dependencies or constraints associated with the external activity. Ensure that they are set up correctly and do not conflict with the scheduling process.
  
  
  Change Activity Status: If the activity is not in a status that allows scheduling, you may need to change its status to enable scheduling.
  
  
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on handling external activities in network scheduling.
  
  
  Contact Support: If the issue persists, consider reaching out to your SAP support team or consulting with an SAP expert who can provide more tailored assistance based on your specific configuration and requirements.
  
  
  Related Information:
  
  SAP Project System (PS): Understanding how external activities are managed within the SAP PS module can provide insights into best practices for scheduling and project management.
  Network Scheduling: Familiarize yourself with the principles of network scheduling in SAP, including how activities are linked and the implications of external activities.
  SAP Notes: Check for any relevant SAP Notes that may address this error or provide additional troubleshooting steps.
  
  By following these steps, you should be able to identify the cause of the CN520 error and implement a suitable solution.