Partial Description of Rosebud's Checkout Process

When a customer presents his or her order at the checkout station, the cashier uses a POS scanner at the end of the belt area to ring up the customer's order in the cash register and to produce a register tape for the customer. After the groceries have been scanned, the cashier obtains the POS register total for the groceries purchased. Then, the customer hits the "enter" key in the pinstripe terminal. A screen display appears that shows the purchase total and asks the customer what type of payment option is desired. The customer selects from three options-credit card, direct debit (through local participating banks), or check authorization-by pressing a key opposite that option.

In the case of credit, the customer runs the credit card through the terminal's magnetic stripe reader. The request for credit authorization is then transmitted to the appropriate credit card company. The credit card company sends back a credit authorization number for the purchased amount. For the debit option, the customer runs a bank debit card through the card reader and then enters his PIN. As in the case of credit purchases, the data are transmitted to the appropriate bank. The bank responds by transmitting back an approval message. For check authorization, Rosebud uses scannable courtesy cards. The courtesy card number and grocery total are transmitted to Rosebud's internal check authorization system. The authorization system looks up the customer in its courtesy card data and notifies the cashier whether or not the check should be accepted.
For the capsule case assigned by your instructor, complete the following requirements:

a. Prepare a table of entities and activities.

b. Draw a context diagram.

c. Draw a physical data flow diagram (DFD).

d. Prepare an annotated table of entities and activities. Indicate on this table the groupings, bubble numbers, and bubble titles to be used in preparing a level 0 logical DFD.

e. Draw a level 0 logical DFD.