How To Fix PEP235 - Nodes NODE_ID = &1 and &2 do not have a predecessor node

SAP Error Message - Details

• Message type: E = Error

• Message class: PEP - Schedule Manager: Messages

• Message number: 235

• Message text: Nodes NODE_ID = &1 and &2 do not have a predecessor node

What causes this issue?

There are at least two nodes without predecessor nodes. This is not
possible.
Technical information: Within a task group (comprising tasks of the same
PARENT_ID), all tasks are connected to one another. The content of field
NSIBLING_ID refers to the node NODE_ID of the next task. Since
such a chain of nodes can necessarily
only begin with one task, it follows that only that particular task
NODE_ID can exist in a task group without a predecessor.
If more than one node NODE_ID does not possess a predecessor (that is,
more than one node has a NODE_ID that is not referenced by any
NSIBLING_ID of another node of the same task group), the task list
is faulty.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message PEP235 - Nodes NODE_ID = &1 and &2 do not have a predecessor node ?

  The SAP error message PEP235 indicates that there is an issue with the predecessor relationship between nodes in a project or process structure, typically in the context of Project Management (PS) or Production Planning (PP) modules. The error message states that two nodes (identified by their IDs) do not have a predecessor node, which means that the system is unable to establish a proper sequence or hierarchy between these nodes.
  Cause:
  
  Missing Predecessor Definition: The nodes in question may not have been properly defined with a predecessor relationship. This can happen if the project structure was not set up correctly or if nodes were added without establishing the necessary links.
  Incorrect Node Configuration: The nodes may have been configured incorrectly, leading to a situation where the system cannot identify a predecessor for one or both nodes.
  Data Integrity Issues: There may be data integrity issues in the project structure, such as missing or corrupted entries in the database that prevent the system from recognizing the relationships between nodes.
  
  Solution:
  
  Check Node Relationships: Review the project structure and ensure that all nodes have the correct predecessor relationships defined. You can do this by navigating to the project or process structure in SAP and checking the hierarchy.
  Define Predecessors: If you find that the nodes do not have predecessors defined, you will need to establish these relationships. This can typically be done in the project management or planning transaction where you can edit the node properties.
  Validate Data: Run data validation checks to ensure that there are no inconsistencies or errors in the project structure. This may involve using transaction codes like CJ20N (Project Builder) or other relevant tools to analyze the project structure.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on how to manage node relationships in your version of SAP.
  Seek 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 setup.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as CJ20N (Project Builder), CJ02 (Change Project), or others that are used to manage project structures.
  SAP Notes: Check for any SAP Notes related to this error message, as they may provide additional insights or patches that address known issues.
  Training and Documentation: Ensure that users involved in project management are trained on how to properly set up and manage project structures to avoid similar issues in the future.
  
  By following these steps, you should be able to resolve the PEP235 error and ensure that your project or process structure is correctly configured.