Batch processing - the traditional date and time based execution of background tasks based on a defined period during which resources were available for batch processing (the batch window). In effect the original mainframe approach transposed onto the open systems environment. Event-driven process automation - where background processes cannot be simply run at a defined time, either because the nature of the business demands that workload is based on the occurrence of external events (such as the arrival of an order from a customer or a stock update from a store branch), or because there is no / insufficient batch window.