form of a screen display and a printed receipt. At the same time, each sales transaction
creates input data for day-end batch processing.
When the store closes, the system uses the sales transactions to produce the daily
sales report and related accounting entries using batch processing. Performing the processing
online before all sales transactions are completed does not make sense. In that
situation, a batch method provides better routine transaction processing, while an online
approach supports point-of-sale processing, which must be done as it occurs.
In the retail store example, both online and batch processing are integral parts of the
information system. Online processing offers an inherent advantage because data is
entered and validated as it occurs, so the stored data is available sooner and always is
up to date. Online processing is more expensive, however, and the effect of computer system
downtime or slowdown while transactions are processed causes far more disruption
than in batch processing. In addition, backup and recovery for online processing are more
difficult. In many situations, batch processing is cost-effective, less vulnerable to system
disruption, and less intrusive to normal operations. Many information systems will
continue to use a combination of online and batch processing for some time to come.