After inventory items and warehouses are established in the NCAS, they can be linked online via the Item Warehouse Entry (IWE) screen. When an item/warehouse connection is established, the item passes from the item file in the Inventory module to the Statewide Item File in the Purchasing module as a stock item. Before an item is associated with a warehouse, transactions involving the item cannot be processed because the item has not been defined to the warehouse for which the transaction is made.