Kitchen Gadgets sells a line of high-quality kitchen gadgets. When customers place orders on the companys Web site, the system checks to see if the items are in the warehouse. The system issues a status message to the customer with out-of-stock items and generates a shipping order with available items to the accounting department. The accounting department will generate an invoice into the system, and the system sends a bill to the customer. Once the customer pays, the system sends an order confirmation to the warehouse. When the order is shipped, the warehouse generates a shipping confirmation to update the stocks, and the system produces an inventory report handled by the accounting department.

please solve it as a level 0, and level 1 and level 2