Figure 9.3 shows the systems flowchart for a hypothetical system that we will use to describe our first set of controls. In our first pass through the system, please ignore the control annotations, P-1, P-2, and so forth. They have been included so that we will not have to repeat the flowchart later when we prepare the control matrix.
The processing starts in the first column of Figure 9.3 with the clerk typing in the input data. Usually, the data entry program would present the clerk with an input screen and then prompt the user to enter certain data into fields on that screen (e.g., customer code, items numbers, and so on).
Note that the first processing square in the data entry devices column “edits” the data before they are actually accepted by the system. The editing is done through various programmed edit checks; these are discussed later in this section. 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. That action triggers the computer to simultaneously:
- Record the input in machine-readable form—the event data disk.
- Inform the user that the input data have been accepted.
To verify that the event data were keyed correctly, the documents could be forwarded to a second clerk who would type the data again. This procedure, called keyverification, was introduced in Documenting Business Processes and Information Systems and will be further explained below. Typically, key verification is applied only to important fields on low volume inputs.
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.