The computerized purchases system operates as follows: Step 1: the user department (that is, the shop or central warehouse) issues a purchase requisition and sends it to the purchasing department at head office. Step 2: the purchasing department issues a purchase order, which it sends to the supplier, and it logs the order in the computer system. Step 3: when the goods are received by Decora (in the shop or at the central warehouse) they are checked, and a receiving report is issued by the warehouse/rece ving department. Details of the goods received are entered into the computer system and matched against the purchase order. Step 4: the financial accounting department at head office rece ves the purchase invoice. This is sent to the user department, which authorizes it and returns it to the financial accounting department. The financial accounting department enters the purchase nvo ce details into the system, which posts the invoice to the purchase ledger. Step 5: the computer system allows payment of the nvoice on y if the details agree to the purchase order in Step 2 above and the receipt of the goods in Step 3 above. Step 6: when the purchase invoice is due for payment, the comouter prints the cheques and remittance notices to the suppliers. Cheques are automatically produced at the due date after the purchase invoice has been posted to the purchase ledger. The partner in charge of the audit has asked you to identify the controls over authorizing purchase invoices details on the computer's standing-data file. He has explained that "application controls" comprise processes exercised by the company's staff and by the computer system. Required: Prepare a memo to the audit partner discussing the following: . the various application controls and control objectives you would expect to see in operation from generating the purchase requisition to the system accepting the purchase invoice the various controls that should be exercised over access to the system from computers in the corporate head off ce and in the shops