Time is of the essence for mainframe operators in the banking, credit, and data processing industries. Much of their processing is time sensitive and a big portion of it is done in the off-hours, either at night or on weekends. In the mainframe world, this period of time is known as "the batch window." Because online systems are frequently dependent on the completion of the batch window before they can be ready for customer transactions, it is vital to keep batch processing times within this window. Thus, the impact on an application's batch processing time is a major consideration when adding new functionality, introducing new products, updating customer or product accounts, creating new reports, and meeting new financial requirements.