Passenger Service System (PSS)

While often called a single system, in reality a modern PSS is a confluence of three distinct and well-integrated systems.

Airline Inventory System

This module handles the number of seats taken on each flight. It defines the number of seats in certain “buckets” or Reservation Booking Designators (RBDs) according to fare class (i.e., first class, economy flex, or economy saver). It interacts with revenue management systems to open or close these buckets to create the maximum yield.

Airline Reservation System (ARS)

This is the database that contains the PNR (Passenger Name Record). While the inventory system counts the seats, the reservation system is in charge of the people. It stores customer information, itinerary information, special service requests (SSRs, such as “Vegan Meal” or “Wheelchair”), and ticket numbers.

Departure Control System (DCS)

The DCS is enabled when the booking window closes and the check-in window opens (usually 24–48 hours prior to flight). It handles:

• Check-in: Punching boarding passes and specific seat numbers.
• Baggage: Tracking checked baggage weight and routage.
• Load control: Calculating the weight and balance of the aircraft in order to ensure safety.
• Boarding: Scanning of tickets at the gate to check the passenger manifest.

It is easy to confuse a PSS (Passenger Service System) with a GDS (Global Distribution System), as they tend to exchange data, but their roles are reversed.

• The PSS is the internal system of the airline (the source of truth).
• The GDS is an external network used by travel agents to access that PSS.

When a travel agent searches for a flight in Sabre (GDS), Sabre will send a message to an airline’s PSS (such as Amadeus Altea) that says, “Do you have a seat?” The Passenger Service System replies and if booked, a PNR is created by the PSS, with the confirmation sent back to the GDS.

The market is dominated by a few massive technology providers.

• Legacy carriers: Full-service airlines (like Lufthansa or British Airways) usually have complex PSS suites (like Amadeus Altea or SabreSonic). These are systems that support complex interlining (connecting flights between different airlines).
• Low-cost carriers (LCCs): Budget airlines (like Ryanair or Spirit) tend to use ‘ticketless’ PSS platforms like Navitaire New Skies. These are streamlined to concentrate on direct sales and ancillary revenue instead of complicated connecting itineraries.