Editing Programmed Airline Reservations System

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{{Infobox software
| name                   = Programmed Airline Reservations System
| title                  = Programmed Airline Reservations System (PARS)
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| developer              = [[IBM]]
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| repo                   = 
| programming language   = 
| operating system       = [[IBM Airline Control Program]] (ACP),<br />[[Transaction Processing Facility]] (TPF)
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| language count         = <!-- DO NOT include this parameter unless you know what it does -->
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| genre                  = [[Airline reservations system|Airline reservation application]]
| license                = [[Proprietary software]]
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}}
'''Programmed Airline Reservations System''' ('''PARS''') is an [[IBM]] proprietary large scale [[Airline reservations system|airline reservation application]], a [[computer reservations system]], executing under the control of [[IBM Airline Control Program]] (ACP) (and later its successor, [[Transaction Processing Facility]] (TPF)). Its international version was known as ''IPARS''.<ref name=":0">Hobson S.J. "ALCS — A high-performance high-availability DB/DC monitor", 1989. {{ISBN|3-540-51085-0}}</ref>

By the 1960s, with the [[American Airlines]] [[Sabre (travel reservation system)|SABRE]] reservations system up and running, IBM offered its expertise to other airlines, and soon developed [[Deltamatic]] for [[Delta Air Lines]] on the [[IBM 7074]], and [[PANAMAC]] for [[Pan American World Airways]] using an [[IBM 7080]]. By 1967/8 IBM generalized its airline reservations work into the PARS system, which ran on the larger members of the IBM [[System/360]] family and which could support the largest airlines' needs at that time (e.g. United Airlines ran about 3000 reservations terminals online in the 1972 timeframe). In the early 1970s IBM modified its PARS reservations system so it could accommodate the smaller regional airlines on smaller members of the 370 systems family. The high performance PARS operating system evolved from [[IBM Airline Control Program|ACP]] (''Airlines Control Program'') to [[Transaction Processing Facility|TPF]] (''Transaction Processing Facility'').<ref name=":0" />

In the early days of automated reservations systems in the 1960s and 1970s the combination of ACP and PARS provided unprecedented scale and performance from an on-line real-time system, and for a considerable period ranked among the largest networks and systems of the era. In the early 1970s major US banks were developing major on-line teleprocessing applications systems and were in urgent need of ACP's high performance capabilities. ACP was made available by IBM to the banking industry in the mid-1970s. This system was used by the great majority of large airlines in the US and internationally; and its smaller 1970's version was used by many smaller regional airlines. PARS (and IPARS) was extremely successful, and it massively improved and revolutionized the efficiency of airlines passenger operations and their profitability.{{citation needed|date=February 2011}}

Along with many other major and regional US airlines, the PARS system was later used by [[Trans World Airlines|TWA]] and [[Northwest Airlines]].<ref>Weiner, Eric, [https://www.nytimes.com/1989/06/11/business/diarams-pan-am-s-nwa-s-1988-route-system-pg-1-chart-comparative-strengths.html "Diagrams of the Pan Am's and NWA's 1988 route system"], The New York Times, Sunday, June 11, 1989</ref>   In this context PARS was also used as a marketing name by TWA when selling their system to travel agencies.
Swiss International Air Lines and Brussels Airlines discontinued using PARS beginning of 2016. IranAir, the Iranian National Airline, discontinued using IBM-ACP/IPARS at the beginning of 2000 due to Year 2000 (Y2K) problem.

CPARS (Compact Programmed Airlines Reservations) was used by smaller airlines (e.g. Icelandair).   Among other limitations (compared to PARS) was a shorter booking horizon of 90 days.{{citation needed|date=February 2011}}

== References ==
{{Reflist}}

== Further reading ==
* Winston, Clifford, [https://books.google.com/books?id=jCfkJUL8oV0C "The Evolution of the Airline Industry"], [[Brookings Institution Press]], 1995. {{ISBN|0-8157-5843-X}}. Cf. p.&nbsp;62.

{{IBM}}

[[Category:IBM software]]
[[Category:Travel technology]]
[[Category:IBM mainframe software]]