This is my first ever DFD that I made after my fair share of learning but I have no way of verifying whether it is correct or not. Although I have taken utmost care to make sure it is right, I may be wrong.
Here is the scenario:
Bebop Records is a mail-order company that distributes CDs and tapes at discount prices to record club members. When an order processing clerk receives an order form, he or she verifies that the sender is a club member by checking the Member file. If the sender is not a member, the clerk returns the order along with a membership application form. If the customer is a member, the clerk verifies the order item data by checking the Item file.
Then the clerk enters the order data and saves it to the Daily Order file. The clerk also prints an invoice and shipping list for each order, which are forwarded to Order Fulfilment.
And here is my diagram: