How To Fix REBDOA003 - &1 is already assigned to &3 in period &2

REBDOA003 - Overview

• Message type: E = Error

• Message class: REBDOA - Messages for Object Relationships

• Message number: 003

• Message text: &1 is already assigned to &3 in period &2

What causes this issue?

You want to assign an object (order, functional location, project,
asset) to a real estate object, although the object is already assigned
to another real estate object at the same time. However, this is not
allowed according to your current Customizing settings (see the IMG
activity <DS:SIMG.REFXV_TIVCACCSET>Make Basic Settings in Company Code
</>).
In the menu option <DS:SIMG.REFXV_TIVBDPM> PM Integration: Make Settings
per Object Type</>, define whether functional locations are to be
created and maintained automatically for each object type.

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?

Change the assignment or restrict it in terms of time.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

REBDOA003 - Details

• The SAP error message REBDOA003 indicates that a specific object (like a cost center, internal order, or another entity) is already assigned to another entity in a specified period. This typically occurs in the context of financial or controlling modules where assignments of objects to periods are strictly controlled to maintain data integrity.
  
  Cause:
  
  Duplicate Assignment: The object you are trying to assign is already linked to another entity for the specified period.
  Period Locking: The period may be locked for changes, preventing any modifications to assignments.
  Incorrect Configuration: There may be configuration issues in the system that lead to conflicts in assignments.
  
  
  Solution:
  
  
  Check Existing Assignments: 
  
  Use transaction codes like KOB1 (for cost centers) or KO03 (for internal orders) to check the current assignments of the object in question.
  Identify the entity to which the object is already assigned.
  
  
  
  Modify or Remove Existing Assignment:
  
  If the assignment is incorrect or no longer needed, you may need to remove