Splitting an order allows you to split onbackorder orders into multiple parcels therefore partially fulfilling any items in an order that are in stock whilst keeping the remaining items on backorder until new stock is sent to the warehouse.
Splitting an order will create a copy of the order with just the items that had allocated stock and this order will be fulfilled by the warehouse. Whilst the original order will contain the items which had no stock allocated. This order will be held on backorder until new stock arrives at the warehouse
The "Split Order" option is only available for orders with "OnBakOrder" status and at least 1 unit allocated. If these requirements are not fulfilled, the option will now show up on the order's details page.