You use the stock transfer order as a replenishment strategy if the material required in a plant is stored in another plant of the same company. Here, when a kanban is set to EMPTY, a purchase order is generated, which requests the other plant to deliver the material required.
When the kanban is set to EMPTY, a purchase order is created in the receiving location and a release order in the delivering plant. The release order is procured and then posted using the goods movement type 351. In the receiving location posting takes place with movement type 101. However, instead of posting the goods receipt, the status can also be set to FULL (then goods receipt takes place in the background).
If the removal from stock in the delivering plant is to be carried out using MM functionality, the vendor indicator must be set to blank in Customizing for Purchasing (Purchase order processing -> Set up stock transport order). If the stock transfer is to be carried out in SD, the appropriate vendor has to be maintained.