16.2 Processes at the checkout
From the point of view of the customer and the checkout operator, a supermarket's ICT system is like the stand-alone computer you saw in Figure 10 in Section 9. The system map in Figure 12 represents this view. The boundary of the system has been drawn tightly, so that we can focus on the important processes being carried out at the checkout. I've called the system the 'checkout system' and there are three components: the customer, the checkout operator and the checkout terminal.
I've also adapted the diagram of the stand-alone computer you saw in Figure 10 to show the checkout system as a block diagram (Figure 13). The computer is now the checkout terminal. However, there is an important difference between the two diagrams in that this computer has two users, the checkout operator (User 1) and the customer (User 2). The reason for this should become clearer as we discuss the processes involved at the checkout.