V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TPF
       Transaction Processing Facility (IBM, MVS/XA)


The Free On-line Dictionary of Computing (30 December 2018):

Transaction Processing Facility
TPF

    (TPF) A real-time mainframe operating
   system released by IBM around 1976.  TPF is particularly
   suited to organisations dealing in very high I/O message
   switching and large global networks.  Current users include
   British Airways (reservations), VISA International
   (authorisations), Holiday Inn, and Quantas.

   TPF was traditionally a 370/Assembler environment although
   the latest, release 4.1, contains C.  Formerly known as ACP
   (Airline Control Program), it was renamed "TPF" to suggests
   its greater scope.

   It is common for TPF sites to use IBM's MVS and VM
   operating systems for off-line processing.

   (1996-08-27)