The Legacy
It takes an airline-industry history lesson to understand why Travelocity and Expedia display fewer flights. Before Orbitz, most travel sites simply put a Web interface on 30-year-old technology. The computer reservation system (CRS) used in most U.S. travel bookings is dominated by old-school companies like Galileo, Amadeus, Sabre, and Worldspan. Orbitz worked with Worldspan during site development and uses Worldspan's technology as its booking engine, but saw too many drawbacks to using a similar technology for flight-searching functions.
If you've ever wondered how your travel agent finds such good deals, or been frustrated while experimenting with online travel sites, the inaccessibility of CRSs might have something to do it. For instance, each CRS system is different, and travel agents receive extensive training in how to properly use the command-line interface and extract the right information from it. People other than travel agents can access CRS through a Web site, but few know a travel agent's tricks of the trade.
For Orbitz, it didn't help that CRSs rely on mainframe computers (Worldspan and Sabre use IBMs, Amadeus uses a Unisys ES7000 Intel-based mainframe, and Galileo uses an SNA-based mainframe). As Orbitz's press materials put it, "using a mainframe to keep up with the dynamic needs of online travel searching is like trying to turn the Titanic around in a bathtub."
A standard search for a trip from New York to L.A. could have two billion possibilities, because a flight could theoretically route through every airport in the country. To minimize transaction time, mainframe operators have optimized the algorithm to search several hundred thousand and a million possibilities. If a mainframe tried to search all two billion combinations, says Orbitz CIO Kevin Malover, "the system would be brought to its knees." An extensive search engine would take computing capacity away from other tasks, like flight booking capability.
Zoghlin is quick to note that he's "not a mainframe basher," describing them as "amazing" and "revolutionary" for their time. But he refers to Moore's Law, which states that the number of transistors capable of being squeezed onto a chip (roughly equivalent to computing speed) doubles every year. With technology improving so quickly, why use systems built decades ago, even if they were good systems in their time?
Beyond Mainframes
To solve the mainframe problem, Orbitz brought in ITA Software, a Cambridge, MA-based travel technology company founded by computer scientists from MIT's Artificial Intelligence Laboratory. Founded in 1996, ITA built its reputation by licensing software to big names in travel technology like Amadeus, Logibro, and SITA.
In 1999, after seeing ITA demonstrate its system at a conference, representatives from the five major U.S. airlines approached ITA about Orbitz. ITA CEO Jeremy Wertheimer, notes that the meeting took place "before [Orbitz] had any employees or anything." Yet, by spring 2000, ITA had signed an agreement to provide the flight search engine for Orbitz.
The group decided to build Orbitz Flight Search Engine with the help of distributed object computing. This technique divides client/server applications into components that can function across different networks and operating systems—nearly the opposite of a mainframe. The benefit is a more flexible, scalable IT infrastructure. For instance, Orbitz has 600 PCs, each running a different part of the system software. If the company finds a problem in one part of the engine, administrators can swap in new PCs and software without having to overhaul everything.
The PCs are Intel boxes that mostly run Linux. Wertheimer says ITA is dogmatic about having Linux as its operating system. The group also feels strongly about adhering to Intel hardware because of its sound performance.
"The actual computation that gets performed at Orbitz is tremendously expensive," explains Wertheimer, "It would be sort of unthinkable on a mainframe." For instance, computer interactions back and forth between the airlines are complicated, as schedules and fares change frequently. Orbitz draws that information from a data center in Atlanta that broadcasts it in real time.
Other travel companies appear to be following Orbitz's lead. In late 2001, Sabre announced that it would move its airline-registration database system from mainframes to Compaq servers, a change that will take Sabre several years and $100 million to implement.
