For STO following are the minimum requirement

The material code should be same at delivering

plant and receiving plant.

Material to be transferred should be created in both the

plants.

Supplying plant is to be created as Plant as Vendor for the

receiving plant.

Receiving Plant has to be created as Customer.

STO pricing procedure to be maintained.

If requirement are fullfilled STO is generated by receiving

plant using docs type NB, sto generated then Delivery,

commercial invoice & excise invoice

While in 3rd party sales it is E1 transaction

Distributor raise PO on manufacturing plant on behalf of

delear,material supplied to delear by manufacturing plant,

delear issue form E-1 to manufacure on receipt of goods &

make payment to distributor who will transfer to

manufacture, cst exempted so we can say distributor is sold

to party & delear is ship to party. Other part is same

delivery commercial invoice & excise invoice, in sto

pricing procedure is as per cast auditors certificate