Intercompany STO - Delivery Quantity Issue

Hello Gurus,

I have setup intercompany STO ( 2 different plants with 2 different company codes)

Intercompany Stock Transport order with billing and shipping:-

Purchase order created for 500 Qty with over delivery tolerance 10% and released it  ->in VL10b , created delivery for 800 qty for that Purchase order-> the Billing done in SD module for 800 Qty

System has created delivery for 500 Qty but user has changed the qty and did the PGI for 800 Qty

MIGo- with Reference to Purchase order for 800 Qty which system should not allow because Good Issue more than the over delivery tolerance 10% defined in PO  

How to stop system in which system should check the overdelivery Tol. ( in this case 50 Qty so total 550) and should not allow delivery more than 550 qty ?

Thanks

SL