Figure 9.5 depicts another hypothetical system. As with Figure 9.3, we make some assumptions. First, we have event data entering the system from a remote location because communications with a data entry system may be from sites away from the computer center. For instance, an existing customer might enter an order through a Web site. Second, we show that the events are typed into the system without using a source document. Naturally, source documents could be used such as they were in Figure 9.3.
Note that this system, unlike the one in Figure 9.3, validates input by reference to master data. Normally, if a user enters valid data such as a valid customer code, the system automatically retrieves certain standing master data such as the customer name and address. Having edited the input, the computer displays a message to the user indicating that the input either is acceptable or contains errors. If errors exist, the user may be able to correct them immediately. Once users have made any necessary corrections, they type in a code or click the mouse button to instruct the system to accept the input. As it did in Figure 9.3, that action triggers the computer to record simultaneously the input and inform the user that the input data has been accepted.
As with Figure 9.3, our flowchart stops at this point without depicting the update of any master data. Certainly our system could continue with such a process. We have not shown it here so that we can concentrate on the input controls.