Sometimes there's a need to have multiple virtual warehouses within a physical building to segregate certain inventory that may have the same sku in order to allocate one sales order to a specific and may be from more than one warehouse. Technically you can use warehouse location however, since you can not allocate sales order by warehouse locations. Hence the use of virtual warehouse. System requires a transfer order for multi warehouse on SO. Alternatively, it creates 2 shipments which results 2 freight bills and potential more cost to the customer. Would be nice to eliminate the transfer order and allow create one shipment with multi warehouse that belong in same Warehouse Building. Another word, allow create shipment by Warehouse Building instead of warehouse.