Question: TD Company TD Company purchases over $10 million of office equipment per year under its "special" ordering system. Individual orders range from $5,000 to $30,000. "Special" orders are orders on low-volume items that have been included in an authorized user's budget. Department heads include in their annual budget requests the types of equipment and their estimated cost. The budget, which limits the types and dollar amounts of office equipment a department head can requisition, is approved at the beginning of the year by the board of directors. Department heads prepare a purchase requisition for the Purchasing Department. TD's "special" ordering system functions as follow: Purchasing. Upon receiving a purchase requisition, one of five buyers verifies that the person requesting the equipment is a department head. The buyer selects the appropriate vendor by searching various vendor catalogs on file. The buyer phones the vendor, requests a price quotation, and gives the vendor a verbal order.
A pre-numbered purchase order is processed with the original sent to the vendor, a copy to the department head, a copy to receiving, a copy to accounts payable, and a copy filed in the open requisition file. When the Receiving Department orally informs the buyer that the item has been received, the buyer transfers the purchase order from the unfilled file to the filled file. Once a month the buyer reviews the unfilled file to follow up and expedite open order. Receiving. The Receiving Department receives a copy of the purchase order. When equipment is received, the receiving clerk stamps the purchase order with the date received, and, if applicable, in red pen prints any differences between quantity on the purchase order and quantity received. The receiving clerk forwards the stamped purchase order and equipment to the requisitioning department head and orally notifies the Purchasing Department.
Accounts Payable. Upon receipt of a purchase order, the accounts payable clerk files the purchase order in the open purchase order file. When a vendor invoice is received, the invoice is matched with the applicable purchase order, and debiting the equipment account of the department requesting the items sets up a payable. Unpaid invoices are filed by due date and, at due date, a check is prepared. The invoice and purchase order are filed by purchase order number in a paid invoice file, and the check is forwarded to the treasurer for signature. Treasurer. Checks received daily from the Accounts Payable Department are sorted into two groups: those over $10,000 and those $10,000 and less. Cheques for $10,000 and less are machine signed. The cashier controls the key and signature plate to the check-signing machine and maintains a record of usage. The treasurer or the controller signs all checks over $10,000 E,2 2009
Required: a. Prepare a context diagram of the existing system.
b. Prepare a physical dataflow ram of the existing system.
c. Prepare a logical data diagram of the existing system.