Question 27. (19 marks)SuperShopper Supermarket ChainThe SuperShopper supermarket chain operates in the following manner. All produce is supplied from the central depot. Every item sold is labelled with a unique code, which is entered by the checkout operator along with the quantity. A disk file from head office contains a record for every item code giving item description and recommended price. Each supermarket is run by a manager who can choose to charge the recommended price or some other price to suit local conditions. Typically this is used to offer “specials”. The computer system therefore keeps a separate file giving special prices for selected items. The manager will maintain this file by adding and deleting items from it. When a customer reaches a checkout, the item code will be checked against the specials file and the price in that file used. In the event that there is no item of that code in the specials file, the price from the head office file will be used. The customer gets a receipt containing the item descriptions, quantity and price.
(a) (12 marks)
Draw a dataflow diagram covering the operation of this system.
(space of 3/4 page)(b) (3 marks)
This system works well for pre-packaged items, which are all the chain currently sells. However, the possibility of expanding the range to fresh food is being considered. In particular it is felt that there would be a market for fresh fish. The customers would choose a fish, possibly even catch one from a tank, and take it to the fish counter for scaling. One anticipated difficulty lies in identifying the type of fish, since the staff may not have the required expertise, and prices of different species might vary widely. It is proposed to develop a computer system to identify fish at the checkout, possibly by capturing an image or by some scientific measurement.For a system of this nature, which development methodology would you use? Give reasons for your answer. (6 lines)
(c) (4 marks)
Until the automatic computer identification system is working adequately, the company is prepared to employ fish experts to identify the fish (visually). It is not possible to have an expert at every supermarket.Describe the equipment required to enable the experts to identify the fish for the checkout staff. (12 lines)