Input, Processing, and Output Controls
The next area of focus is input, processing, and output controls. When detecting an error in an IT application, there are three points where it can be identified. It can be detected during the input of information into the system, known as input control. It can be detected during the processing phase by the system, known as processing control. Or it can be identified in its final output, like a final report, called output control. Let’s discuss each of these controls in detail.
Firstly, input controls are tools that help detect errors when information is being input into the system. Another term for input control is an edit check. The first type of input control is a field check, which verifies that the format of the input information is correct. For example, when someone is entering their credit card information online, it will ensure that the data is 16 numbers long, and if not, it will generate an error.
The next type of input control is a validity check, which compares input information to a database. For instance, when an employee logs in for the day and enters their employee ID, the validity check compares what they input to the database to verify if an employee with that ID actually exists.
Another input control is a limit test, also known as a reasonableness test. This type of control uses a specific range of information to evaluate the input. For instance, if an employee is entering their number of hours worked for the week and they enter 120 hours, the input control, perhaps designed to expect between 20 and 60 hours, won’t allow this information to be input, deeming it unreasonable
Next, let’s talk about output controls and three key terms: hash total, financial total, and record count. A hash total is the sum of non-financial information (i.e., numbers that don’t make any sense to add up). For instance, if you add up the customer IDs, the total is irrelevant information, and that’s a hash total. The financial total is the sum of financial information, such as the sum of the purchase amount. This is valuable information. The record count is the number of records. If there are three rows in a database, then the record count is three.