This undoubtedly saves time but does pose internal control problems, as the segregation of duties between data capture and data entry is forgone. Other internal control procedures must be implemented to compensate for this. A common means by which this is done is the recording of transaction logs, which contain extra info regarding every transaction that is keyed into the system. The transaction log enables an auditor to see the time of entry, user authorization etc of every transaction keyed in. We can futher divide paperless input systems into those that require manual data entry, and those that incorporate automatic identification systems.
Processing then occurs automatically.
Your local supermarket provides a good example of this. Each item purchased is swiped through the bar code reader which automatically updates the sales and inventory accounts. Many other forms of automatic identification are used. If an invalid code is used when preparing a purchase order, the computer will reply with an error message. As mentioned previously, paper based systems are invariably batch oriented.