Items havent been deducted in Subcontracting

Hello everyone,

I need some help with subcontracting process.

I have an item which has a BOM and supply raw material for purchase option checked. When I create a purchase order of this item and generate the purchase receipt I can see this item added in the warehouse previously selected, but I dont see the items of the BOM deducted in the source warehouse (subcontractor vendor).

In my process, I do some stock entries (material transfers) to my subcontrator warehouse before generating the purchase order, due to the material doesnt arrive to our facilities at the same time and once we have them, we send them. The thing is that, I don´t do a stock entry (send to subcontractor) and I don´t know if I´m doing well or not.