How To Fix PPEACT642 - Hierarchy relationship is not allowed between &1 type &3 and &2 type &4

SAP Error Message - Details

• Message type: E = Error

• Message class: PPEACT - Messages for iPPE ACT Application (Activities)

• Message number: 642

• Message text: Hierarchy relationship is not allowed between &1 type &3 and &2 type &4

What causes this issue?

The required hierarchy relationship is not available in Customizing.

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 PPEACT642 - Hierarchy relationship is not allowed between &1 type &3 and &2 type &4 ?

  The SAP error message PPEACT642 indicates that there is an issue with the hierarchy relationship between two objects in the system. Specifically, it suggests that the relationship you are trying to establish between the two specified types is not permitted. This error typically occurs in the context of SAP's Product Lifecycle Management (PLM) or similar modules where hierarchical relationships between objects (like materials, BOMs, or other entities) are defined.
  Cause:
  The error message PPEACT642 is triggered when:
  
  You are trying to create a relationship between two object types that are not compatible. For example, you might be trying to link a material to a BOM in a way that is not allowed by the system's configuration.
  The object types involved do not support the hierarchical relationship you are attempting to establish. This could be due to predefined rules in the system or configuration settings that restrict certain types of relationships.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Object Types: Review the object types involved in the relationship. Ensure that they are compatible and that the relationship you are trying to create is valid according to SAP's guidelines.
  
  
  Review Configuration: If you have access to the configuration settings, check the settings for the object types involved. Ensure that the hierarchy relationships are correctly defined and that there are no restrictions preventing the relationship.
  
  
  Consult Documentation: Refer to SAP documentation or help resources for the specific module you are working with. This can provide insights into valid relationships and any constraints that may apply.
  
  
  Use Alternative Relationships: If the relationship you are trying to create is not allowed, consider whether there are alternative relationships that can achieve the same goal without triggering the error.
  
  
  Contact SAP Support: If you are unable to resolve the issue through the above steps, consider reaching out to SAP support for assistance. They can provide more detailed insights based on your specific configuration and usage.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide additional context.
  Transaction Codes: Familiarize yourself with transaction codes related to the objects you are working with (e.g., CS01 for BOM creation, MM01 for material creation).
  User Forums: Engage with SAP community forums or user groups where similar issues may have been discussed, and solutions shared.
  
  By following these steps, you should be able to identify the cause of the PPEACT642 error and take appropriate action to resolve it.