Delivery type "LB" and MRP

Hi All

I work on the APO side and iam not thorough with MM . I have a question about the subcontracting scenario .

We provide components to the subcontractor who then makes the finished products and ships them to our plant. Let us assume we have a subcontracting requirement for 100 CS. We now create a delivery (ME2o) to the subcontractor for 100 CS ( delivery type LB) . When we look at MD04 the delivery created for 100 CS is not offsetting the subcontracting requirement of 100 CS. So we now have a demand of 100 + 100 = 200 CS which is actually not the case. Is this a standard SAP behaviour ?

I believe whenever we issue goods to the vendor the stock at subcontractor location (MatSub) increases and the dependent demand gets offset by stock at subcontractor location . But why doesnt a delivery to the vendor offset the dependent demand ? Please help

Thanks

Saradha