Application Modernization

Application modernization improves software the organization already depends on, rather than adding new systems. An application may still do its job, but it runs on aging infrastructure, is hard to change, or cannot easily connect to newer services. Modernization addresses these problems through changes that range from moving the application to cloud infrastructure, to restructuring its code, to rebuilding it around a new architecture. The goal is to keep the business value the application provides while removing the technical limits that hold it back.

Most organizations run applications built over several decades, using technologies and designs that made sense at the time. Many of these applications are too valuable to retire but too costly or slow to leave as they are. Application modernization gives them a longer and more productive life. For enterprise architecture and IT finance, it is one of the main ways to reduce run costs, speed up delivery and lower risk across the application portfolio.

Definition of Application Modernization

Application modernization is the practice of updating an existing application's infrastructure, code, architecture or delivery methods to bring it in line with current standards and needs. It differs from building new applications because it starts from software already in use, with existing users, data and integrations.

It overlaps with legacy system modernization, which focuses on the oldest and most constrained systems, but it also applies to newer applications that no longer fit the organization's target architecture.

Common Approaches

Rehosting, sometimes called lift and shift, moves an application to new infrastructure such as the cloud with minimal changes. It is quick but delivers limited benefits beyond the infrastructure move.

Replatforming makes targeted changes, such as moving to a managed database or container platform, to gain some cloud benefits without redesigning the application.

Refactoring restructures the code to improve maintainability and performance, often by separating a large application into smaller components. Rearchitecting redesigns the application around a new architecture, such as microservices or cloud-native architecture.

Where none of these is worthwhile, the application may be replaced with a packaged product or cloud service, or retired.

What Modernization Changes

Infrastructure modernization moves applications to more flexible and cheaper platforms. Architecture modernization changes how components are structured and connected.

Integration modernization replaces fragile point-to-point connections with APIs or an integration platform, making the application easier to connect to others.

Delivery modernization introduces automated testing, deployment pipelines and monitoring, which shorten the time needed to release changes. Many organizations find this delivers as much benefit as changes to the application itself.

Importance of Application Modernization in Enterprise Architecture

Modernization reduces the cost of running existing applications, through cheaper infrastructure, fewer licenses for outdated software and less manual effort. Savings often come from the operating model as much as the technology, since modern platforms need less hands-on maintenance.

It speeds up change. Applications with modern architecture and automated delivery can be updated in days or weeks rather than months, allowing the business to respond faster. Faster change also lowers the cost of every future project that touches the application.

It also reduces risk by moving applications off unsupported technology, improving security and making systems easier to monitor and recover. Modern applications are also easier to staff, since the skills they require are more widely available.

Choosing the Right Approach

The right approach depends on each application's business value, technical condition and expected future. A valuable application central to future strategy may justify rearchitecting, while a stable one with few changes may need only rehosting.

Models such as the TIME model help classify applications. Those marked migrate are the usual candidates for modernization.

Cost comparisons should cover several years, including one-time modernization costs and changes in annual run costs, so that options with higher upfront costs but lower long-term costs are judged fairly.

Common Pitfalls

Rehosting without further changes can move costs to the cloud without reducing them, especially if applications are not resized to fit their actual use.

Ambitious rebuilds can take years and absorb budgets intended for other priorities, particularly when business requirements change during the program. Users may also wait a long time before seeing any improvement, which weakens support for the program.

Modernizing applications that should have been retired wastes effort, so a portfolio review should come before any modernization program. Application rationalization often removes a significant share of candidates before work begins.