Legacy System

The travel industry was one of the first industries to go digital, which is ironically how the industry is now dependent on the oldest of all codes.

At the heart of most airlines and GDSs stands TPF (Transaction Processing Facility), which is a high-volume, low-latency transaction processing IBM operating system. It is incredibly efficient—it can process hundreds of thousands of transactions per second with almost zero failures. This is why when you stare at a travel agent’s screen, you will still often see the green screen or command-line interface (CLI) based on cryptic codes (cryptic commands) such as A10OCTJFKLHR rather than a modern graphical interface.

Legacy systems are a Catch-22 for travel innovation.

• Pros: They are battle-tested. They deal with the enormous complexity of interlining (connecting flights) and library (inventory management) with a stable like no other.
• Cons: They are rigid. They were built in an era when ticketless travel was unheard of. Adding a new feature, such as selling a “pet in cabin” add-on, or a change in baggage rule, often means changes made by hard coding in the mainframe, which is slow and costly and requires a declining workforce of specialized developers.

Since ripping out the core mainframe is too risky (compared to changing the engine of a plane while flying), the industry uses middleware.

Travel tech companies develop modern API layers, which wrap around the legacy core.

• Core: The heavy lifting (math and logic) is still performed by the mainframe.
• Wrapper: An API layer is converting the old code (EDIFACT/Teletype) to modern languages (XML/JSON).
• Interface: The consumer perceives a sleek mobile app or website, with no idea that there is a 40-year-old mainframe processing the request in the background.