Stock on components with subcontracting case with source location in PPDS

Hi,

With the subcontracting PPM usage PPDS, I get requirement and planned replenishment on subcontractor location , but when I do the comparizon between the stock of component sent to supplior ( ECC transaction MBLB ) and the stock in APO/RRP3 , I get the stock in plant location instead of getting it in vendor location, where the immediate replenisment is run . The added value of this scenario being to be able to plan also the stock transfer of component to vendor, I assume that we have to use stock user exit to get this stock in the vendor location ?

Kind regard,

Christin