How To Fix IW491 - Purchase order already created: Reassignment not possible

IW491 - Overview

• Message type: E = Error

• Message class: IW - Order Processing

• Message number: 491

• Message text: Purchase order already created: Reassignment not possible

What causes this issue?

You want to reassign a material from one order operation to another.
This is not possible, however, because the account assignment at
operation level is activated for this order type. Since a purchase order
has already been created for this material and the costs have been
updated for the order operation, you cannot reassign this material to a
different order operation.

System Response

The material cannot be assigned to another operation.

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

IW491 - Details

• The SAP error message IW491: Purchase order already created: Reassignment not possible typically occurs in the context of maintenance orders or service orders when you attempt to reassign a maintenance order to a different cost center or internal order after a purchase order has already been created for that maintenance order.
  
  Cause:
  The primary cause of this error is that once a purchase order (PO) is created for a maintenance order, the system locks certain fields to maintain data integrity. Reassigning the maintenance order to a different cost center or internal order is not allowed because it could lead to inconsistencies in accounting and reporting.
  
  Solution:
  To resolve this error, you can consider the following approaches:
  
  
  Check Purchase Order Status: Verify if the purchase order is still open or if it has been fully processed. If it is still open, you may need to cancel or delete the purchase order before attempting to reassign the