Subcontracting flow

Hi gurus,

is it possible to send component ti subcontractor without creating a purchase order for the material to br produced? For example: i want to order to production of 10 PZ of material A and send to subcontractor the material B by using a PO with the material A and the material B as component in BOM. Then, if i need to send an other quantity of material B to produce always the same order (10 PZ) how i can do? I don't want to create an other PO per per material A.

thank you

Marco