Question

How can I draw a flow chart and a DFD (Level "0") of the following narrative?

Each morning the ERP system displays to the buyers in the Purchasing department the list of inventory products that have reached their reorder point. The buyers then select a vendor for each product from the vendor master file. They prepare a Purchase Order for the product and save it in the P.O. file and update the inventory file to show it was ordered. They print and send a copy of the P.O. to the vendor.

When goods are received at the Receiving Dock, the Receiving Clerk uses the P.O. number on the packing slip which was sent by the vendor with the goods to retrieve and display the P.O. information. The Receiving clerk records the quantity received on a receiving report transaction file and updates the P.O. to show that the goods were received.

When a Vendor Invoice is received, Accounts Payable clerk enters the P.O. number and the computer retrieves it from the P.O. file. The clerk makes sure the order has been marked as received and then compares prices on the P.O. with the vendor invoice. If the Vendor Invoice is for the quantity received at the price on the P.O., the AP clerk enters the liability and the due date and the computer saves it to the AP file and updates the P.O. file (changing the status to show it was recorded as a liability). The computer updates the Inventory file to increase quantity on hand by the quantity received.

Each morning the Cash Disbursements clerk queries the AP file to find the ones that are due. Cash Disbursements selects the vendors to be paid, the computer prints a check and the Cash Disbursements clerk sends the vendor the check. The computer records the check in the cash disbursements file and updates the AP to show that it has been paid.  

Answer 1