The customer | Computer Science homework help

The customer browses the aisle, selects his book(s), then stands in line at the check-out counter. The cashier takes the book(s) from the customer, reads the price from the cover, then key punches the price into the POS terminal. If the price is missing the cashier summons the clerk from the Warehouse Department to check the price. Invariably, the Warehouse clerk will check with the Accounting Department to verify the price of the book.
Once the price is verified the cashier proceeds to key punch the price. The customer tenders payment in cash, cheque or by credit card once he is told the total owed. After payment is made, the books are handed to the customer. If the customer had brought a bag into the Bookshop, he will collect it from the Baggage Storage Unit before leaving the building.
Draw the context diagram of the check-out process. Draw the diagram from the perspective of the cashier.