"We're having a heart transplant," said United's Shama Patel, business program manager of the Horizon Project, a service-oriented architecture (SOA)-fueled modernization effort by United Airlines and Lufthansa.

The existing system needed to be replaced. It's 40 years old, built in Assembly language and still green-screen-based (even with a prettier graphical interface glued on top). The back end is no longer scalable for today's needs and it doesn't integrate well with...well, with anything, explained Patel. In addition, each airline and other travel providers(think Travelocity) had disparate systems that didn't talk with one another, and they needed to do so. With customer demands for modern technology (such as, "Why can't I check in using my BlackBerry?"), it was time for a change. (Need a good primer on SOA? Read The ABCs of SOA.)

Lufthansa and United are partnering to develop a common platform that will be used by both airlines and, eventually, also used by other members of the Star Alliance. It'd be easy to dive into the technologies they're using to accomplish this, and to describe the IT architecture. But in Patel's presentation, she urged IT leaders to look at the business challenges rather than code and servers. That's what we talk about here.

The modernization project, dubbed Horizon, is huge. When it rolls out, it will impact 20,000 people in 350 locations in a three- to four-year time frame, and it will touch 20 company divisions. All while they're trying to get people on the plane, she added.

Horizon initially focused on three major back-end functions: sales, planning and departure management. That'd be mission critical enough for any enterprise since "the reservations system holds the customer through the whole journey," said Patel. But, she added, "What you start off with isn't how it transpires."

"As we worked on the back-end system, we realized we also had to replace the front end," she said. The new back end wouldn't be able to interact with the old front-end—and as part of the new system architecture, they needed an abstraction layer in the middle. As a result, the larger-than-expected Horizon project also impacts the integrated agent portal, another green-screen application that's 15 to 20 years old with plenty of cryptic commands; that's the application the gate agent pounds on when she's trying to change your flight. Horizon also affects the corporate intranet, real-time systems for flight status and baggage systems—and plenty more. (Also read Tips to Avoid SOA Implementation Problems.)

The impetus for change wasn't all technological. Currently, it takes seven weeks of training to prepare a new gate agent for the job, with a turnover of 50 percent. Younger employees are less patient with the old computing paradigms. (One can almost hear them complaining, "Green screen? How gross!")

So, concluded Patel, "We needed a heart transplant and a face lift—at the same time!"