How To Fix CN820 - No work center assigned to predecessor

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 820

• Message text: No work center assigned to predecessor

What causes this issue?

You want to calculate the time interval of the relationship as a
percentage of the duration of the predecessor. But no work center has
been entered for this activity and therefore no calendar is available
to perform this calculation.

System Response

The function is carried out. If you have not entered a work center for
the predecessor, the system uses the factory calendar to calculate the
time interval that you have maintained in the network header or the
header of the standard network.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN820 - No work center assigned to predecessor ?

  The SAP error message CN820 ("No work center assigned to predecessor") typically occurs in the context of project management and production planning when there is an issue with the assignment of work centers in a network or activity within a project. This error indicates that the predecessor activity does not have a work center assigned, which is necessary for scheduling and resource allocation.
  Cause:
  
  Missing Work Center Assignment: The predecessor activity in the project network does not have a work center assigned to it. This can happen if the activity was created without specifying a work center or if the work center was deleted or not properly configured.
  Incorrect Configuration: The work center may not be correctly set up in the system, or it may not be valid for the type of activity being processed.
  Data Inconsistencies: There may be inconsistencies in the data related to the project or network, such as missing or incorrect links between activities and work centers.
  
  Solution:
  
  
  Assign a Work Center:
  
  Go to the project or network activity where the error occurred.
  Check the details of the predecessor activity.
  Assign a valid work center to the predecessor activity. This can usually be done in the activity details screen under the "Basic Data" or "Work Center" tab.
  
  
  
  Check Work Center Configuration:
  
  Ensure that the work center you are trying to assign is correctly configured in the system.
  Verify that the work center is active and has the necessary parameters set up (e.g., capacity, cost center).
  
  
  
  Review Project Structure:
  
  Check the overall structure of the project or network to ensure that all activities and their relationships are correctly defined.
  Make sure that all predecessor and successor relationships are properly established.
  
  
  
  Data Consistency Check:
  
  Run a consistency check on the project or network to identify any other potential issues that may be causing the error.
  Use transaction codes like CN22 (for network activities) or CN41 (for project structure) to review and correct any inconsistencies.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation or help resources for additional guidance on managing work centers and project activities.
  
  
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as CN21 (Create Network), CN22 (Change Network), and CN41 (Display Project).
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  User Roles and Authorizations: Ensure that you have the necessary authorizations to make changes to work centers and project activities.
  
  By following these steps, you should be able to resolve the CN820 error and ensure that your project activities are properly configured for scheduling and resource allocation.