employee sitting at the counter welcomes the customer and asks for the
customer's loyalty card. The card has a bar code identifying the customer.
Once the bar code is read, the system checks for the code and displays the
name of the customer on the screen.
All the products that the customer wants to buy are read through the bar
code reader. For each product it is possible to insert the quantity to speed up
the activity when several items of the same product are present. In case of
problems the employee can type in the product code, for instance when the
bar code is scratched or unreadable. When all the items have been read, the
receipt can be printed with the sum to be paid by the customer. This closes
the transaction with the current customer, and the next customer in line
can be served.
The market manager must be able to look at the statistics regarding the
sales by day, by employee and by customer. In addition it must be possible
to associate the customers with the products they bought to study their
The main feature of the system is supporting the employee activities at the
counters. These activities are described by three use cases as depicted in
Figure 14.1. Acquisition involves the employee and the customer, but only
the employee interacts with the system. Connect and Disconnect are
performed by each employee at the beginning and end of each shift.
The system manages information related to three main entities: employee,
customer and product. Information about sales must be recorded to keep
track of the sales and to update the quantity of products available in the store.
Figure 14.1 Main use cases