Transaction Processing Facility

Transaction Processing Facility (TPF) is an IBM real-time operating system for mainframe computers descended from the IBM System/360 family, including zSeries and System z9.

TPF delivers fast, high-volume, high-throughput transaction processing, handling large, continuous loads of essentially simple transactions across large, geographically dispersed networks.

While there are other industrial-strength transaction processing systems, notably IBM's own CICS and IMS, TPF's specialty is extreme volume, large numbers of concurrent users, and very fast response times. For example, it handles VISA credit card transaction processing during the peak holiday shopping season.

The TPF passenger reservation application PARS, or its international version IPARS, is used by many airlines. PARS is an application program; TPF is an operating system.

One of TPF's major optional components is a high performance, specialized database facility called TPF Database Facility (TPFDF).

A close cousin of TPF, the transaction monitor ALCS, was developed by IBM to integrate TPF services into the more common mainframe operating system MVS, now z/OS.

TPF evolved from the Airline Control Program (ACP), a free package developed in the mid-1960s by IBM in association with major North American and European airlines. In 1979, IBM introduced TPF as a replacement for ACP — and as a priced software product. The new name suggests its greater scope and evolution into non-airline related entities.

TPF was traditionally an IBM System/370 assembly language environment for performance reasons, and many TPF assembler applications persist. However, more recent versions of TPF encourage the use of C. Another programming language called SabreTalk was born and died on TPF.