Questions about Returnable transport packaging

Hi Expert,

I had read about Returnable transport packaging in sap and i had some questions i dont know if it is applicable in SAP or not.

- is there any automatic process for creating the returnable item automatic in migo while i receive the goods or there any way i make a relation between the goods and the vendor so when i buy this goods from this vendor and i set a returnable item in migo it calculate the qty depend on the aty of the goods ex. for each 10 KG there are 1 box as a returnable.

- why i need to add the vendor for each returnable item in migo ?? why it cant be adapt from the PO??

- when i make 502 and i enter the returnable material with batch why i need to enter the vendor even though the vendor number is save in batch.