3695588 - Why can the Sales Order quantity field still be changed after billing creation or delivery creation?

Why is the SO quantity still editable even after billing creation and the sales order status being set to completed? 

• SAP S/4HANA Cloud All versions 

1. Logon to the SAP S/4HANA Public Cloud system with the role: SAP_BR_INTERNAL_SALES_REP.
2. Access Sales Order Modification: Execute Transaction Code VA02 and the Sales Order number.
3. Verify Processing Status: Navigate to the item detail level and confirm that the item is; Delivered and/or Invoiced.
4. Attempt Quantity Revision: Access the Item Detail or Schedule Line screen and attempt to revise the value in the Quantity field.
5. Confirm System Behavior: Observe that, despite the complete processing status, the Quantity field remains editable. Upon execution of the quantity change, the system issues warning message but permits the action to be saved.

Standard System Design: This is the default SAP behavior - the order quantity normally remains ready for input and can be changed by users even after delivery and billing.

The system initiates a mandatory warning detailing the potential impact of the quantity revision on all associated follow-up dependencies.

The final authorization to execute the quantity increase or reduction rests with the end user, who assumes responsibility for the resulting modification. This architecture is designed to accommodate and support critical, legitimate business requirements, including necessary data corrections and operational adjustments.

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