Using planning methods B (Order Point System) and C (Refilling Level) you can create a process to replenish the inventory at one site with inventory from another.
Internal replenishment requires the receiving site to be identified as a customer (with a customer record) and the supplying site to be identified as a supplier (with a supplier record). When inventory at the receiving site is depleted to the specified level, an internal purchase requisition can be generated. The requisition is converted to an internal purchase order for the supply location. On satisfactory validation of the purchase order, the supply location creates a customer order on which delivery and documentation addresses are defaults taken from the receiving site's customer record. Activation of the customer order confirms the purchase order and causes a shop order or purchase requisition to be created, as applicable, for each line item. Manufactured parts are delivered directly to the receiving site. Purchase parts can be specified for delivery to the supplying site or for drop-shipment to the receiving site. The supplying site also invoices the receiving site, if they belong to different companies. If they belong to the same company, no invoice needs to be done. When the parts are delivered to the receiving site, they are reported received via normal receipt procedures.
The flow at internal inventory refilling.