How To Fix UCS0401 - Task &1: Explicit predecessor &2 is not a technical predecessor

SAP Error Message - Details

• Message type: E = Error

• Message class: UCS0 - Messages for Status Management

• Message number: 401

• Message text: Task &1: Explicit predecessor &2 is not a technical predecessor

What causes this issue?

Technical preceding task relationships between the relevant tasks result
from the Customizing settings of <LS>reclassification</> and <LS>
allocation</> methods.
Example: Task A uses method M and task B uses method N. The target
assignment of method M also occurs in the trigger for method N. As a
result, task A is a technical predecessor of task B.
The function <LS>Check Preceding Task Relationships</> determines the
technical preceding task relationships for <LS>reclassification</> and
<LS>allocation</> tasks and checks the technical preceding task
relationships for consistency against the settings for the explicit
preceding task relationships that you specified in the process view of
the consolidation workbench under the "Consolidation Monitor ->
Preceding Task Relationships" node.
You have specified that task &V2& is an explicit predecessor of task
&V1&. However, task &V2& is <ZH>not</> a technical predecessor of task
&V1&.

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?

Check the settings for the preceding task relationships and, if
necessary, remove task &V2& from the definition of the preceding tasks
for task &V1&.

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 UCS0401 - Task &1: Explicit predecessor &2 is not a technical predecessor ?

  The SAP error message UCS0401 indicates that there is an issue with task dependencies in a project or a network. Specifically, the message states that an explicit predecessor task (task &2) is not recognized as a technical predecessor for the task in question (task &1). This typically occurs in project management scenarios where tasks are linked based on their dependencies.
  Cause:
  
  Incorrect Task Linkage: The predecessor task may not be correctly defined or linked to the successor task. This can happen if the predecessor task is not in the same project or network.
  Task Status: The predecessor task may be in a status that does not allow it to be a valid predecessor (e.g., it might be completed, canceled, or not yet started).
  Task Type: The predecessor task may not be of the correct type that allows it to be a predecessor (e.g., it might be a milestone or a non-technical task).
  Data Integrity Issues: There may be inconsistencies or errors in the project data that prevent the system from recognizing the predecessor relationship.
  
  Solution:
  
  Check Task Definitions: Verify that the predecessor task (task &2) is correctly defined and is part of the same project or network as the successor task (task &1).
  Review Task Status: Ensure that the predecessor task is in an appropriate status that allows it to be a valid predecessor. If necessary, change the status of the task.
  Correct Task Type: Make sure that the predecessor task is of a type that can be a valid predecessor. If it is not, consider changing the task type or selecting a different predecessor.
  Re-establish Dependencies: If the predecessor relationship is incorrect, you may need to delete the existing dependency and re-establish it correctly.
  Data Consistency Check: Run data consistency checks in the project management module to identify and resolve any underlying data integrity issues.
  
  Related Information:
  
  Transaction Codes: You can use transaction codes like CJ20N (Project Builder) or CJ02 (Change Project) to view and modify project tasks and their dependencies.
  Documentation: Refer to SAP documentation on project management and network planning for more details on task dependencies and project structures.
  SAP Notes: Check for any relevant SAP Notes that may address specific issues related to this error message or provide patches and updates.
  
  If the issue persists after following these steps, it may be beneficial to consult with your SAP support team or refer to SAP community forums for additional assistance.