Sub-Contarcting External Operation Process

Dear Experts,

I have created one production order for the maerial FIN where in one of my operations(5th) is Externally processed at vendor out of 10 Operations.

When I save the production order Sub contracting Purchase requisation has been created with out any material for the 5th Operation.

I Have the following materials in my BOM

Finised Matearial--FIN

Raw material------RAW

I have done the following business processes

1) I have Released the Production order

2)Goods issue (RAW) to the production order

3)Confirmed all the operations up to 4th operation

The unfinished material which I got upto 4th Operation has to be sent out to external vendor -

How to process ater this ????

Pls. suggest with step by step procedure.

Thanks & regards

KK