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Legacy application modernization projects: Proceed with caution

Today, many legacy application modernization projects are actually migrations to cloud apps. Experts warn that no single tool works for every project.

As IT organizations undergo legacy application modernization projects, they must understand what approach they want to take and what they are trying to achieve. Although plenty of tools are available, few of them result in a modernized application, according to Gartner analyst Dale Vecchio and other experts. In addition, today the lines are blurred between application modernization and migration to cloud applications.

Making sense of application modernization tools is no easy task. No single tool will work for every project and, experts warn, even the right tool won't get you across the application modernization finish line.

Choosing the right tool for legacy application modernization

Choosing the right tool "depends on where you're coming from, and where you're going to,” Vecchio said. "There are a variety of tools depending on the approach you want to take." Vecchio defines three primary approaches to legacy application modernization:

  • Non-invasive application modernization involves exposing an app to be consumed in new ways, such as through a service or Web front end.
  • Invasive modernization involves "code transformation, from an old language to a new one; COBOL to a new modern language, usually Java or C#. It's the same app implemented on a completely new stack," he said.
  • Migration is, at essence, a rip-and-replace approach. Today, that usually means that legacy, on-premises applications are replaced by cloud applications.

Eighty percent of legacy application modernization projects today are just migration, according to John David Head, director of enterprise collaboration, PSC Group, a technical and business consultancy largely focused on software modernization. He said PSC sees businesses that have a legacy platform that's problematic -- in costs, performance, etc. -- and they are not looking to vendor updates as solutions. For various reasons, he said, they want to go to another platform. "That's not modernization," he said.

Vecchio agreed, noting a few differences between simple legacy application migration and full-on modernization projects. If a business wants only to move to a different package, for example, they're focused on how to map the existing functions to the package, identify the gaps and decide how to fill them.

True app modernization involves much more than migration. For example, Head said, "The migration of collaboration apps from one technology platform to another offers a unique opportunity to modernize apps, update processes, improve security and prepare for a more mobile driven and dynamic future."

The perils of invasive software modernization

Unfortunately, using tools for what Vecchio calls invasive application modernization doesn't get IT organizations much closer to modernization than migrating from one app to another. "Transformation of the technology alone doesn't really cut it. It's an OK start, but the way you implement old legacy apps is different than the way you do it in the new world, so when you just do a transformation you don't get the app you wanted," Vecchio said.

Capgemini's Ron Tolido agreed. "Of course, you can use tools that pick up an existing application and immediately transform it to a next-generation application, but in practice that's not really what you want," said Tolido, senior vice president, group CTO office, and advisory and architecture lead of the global insights and data practice for Capgemini. "If it's already a sausage, you cannot turn it into a pig again. It's a little bit too late. If there's an old application, you don't want to automatically turn it into something new. There are tools that do it, but it's quite awkward."

That said, it is important that IT organizations understand what legacy application modernization tools can and can't do. "My opinion is that what the tools do best is migrate the data. What they attempt to do is move the business functionality. We have found that most of that works very poorly," Head said.

Outsourcing legacy application modernization projects

Instead of using a tool themselves, Vecchio said most IT organizations he speaks to prefer to outsource legacy application modernization projects to service providers. "No one wants to spend money on a tool to get from point A to point B because when they get to point B, what are they going to do with it?" Vecchio asked. "They don’t have the resources or skills, so they look to service providers to support them."

Still, it's important that IT organizations understand what it takes for true application modernization to take place. PSC Group works with most, if not all, of the application modernization tool vendors. "I'm not disparaging them in any way," Head said. Often, however, there's a huge gap between the customer's expectation of what they want and the reality of what tools can do in migration. For example, the customer may walk in and ask for a simple migration, but the customer adds that the new app has to fit with the existing platforms. "If the customer wants customization, I need to go through a modernization process to build a custom experience," Head said. That's why businesses and internal IT or third-party service providers must agree on requirements. "That level set is really, really important," Head said.

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