In-Depth

Three-pack choice for modernization

• By Alan Joch
• June 1, 2005

Modernization projects come in many varieties, as do the reasons to start the makeover in the first place. Enterprises may wish to boost performance, transition from technologies no longer being supported, or extend the reach of existing applications by integrating them with new programs built with Java or other modern platforms. Extending legacy apps, rather than calling in the virtual bulldozer, appeals to enterprises because these applications are proven after perhaps decades of battle hardening, and because they’re full of important business and customer information.

Too bad they’re showing their age.
When enterprises choose modernization over euthanasia, they have three main choices, says Kevin Kelley, senior technology solutions architect for Avanade, a systems integrator. One is rehosting, where companies just move their legacy code to new platform. “The pro is you can reuse the code; the con is you’re not adding any new capabilities to the existing application,” he says. “You may be reducing maintenance costs, but you aren’t actually modernizing the application architecturally.”

Choice two is code conversion. This might mean converting a COBOL app for a mainframe to running it in the Microsoft .NET framework. “Now your legacy application is on a new platform, and you have better interoperability with more modern systems and architectures, but the cons are you probably haven’t updated your internal architecture, so maintenance may still be difficult,” Kelley adds.

Companies that choose re-hosting or code conversion do so primarily because these options are among the least expensive modernization alternatives.

The third alternative is full-scale rebuilding of the legacy app to run on a new platform within a modern architecture. This brings new extensibility for the foreseeable future, but it comes at a cost that can cause sticker shock.

Fortunately, that’s changing, as EMI and others are learning, thanks to Web services and SOA. These maturing technologies allow companies to expose their legacy code as services that combine the best of the old and the new. “Companies are valuing their legacy code more,” says Linda Cole, iSeries tools innovation manager for IBM. “In the past, businesses might have looked for a new solution rather than looking to what they have and reuse and re-architecture it.”

Back to feature: Enterprise Modernization: New Life for Old Apps