What Is a Legacy System?

A legacy system is any outdated software or hardware that it’s still in use. Although the term may imply it, a legacy system isn’t necessarily an aged technology. It can be a system that lacks vendor support or doesn't meet an organization's evolving requirements.

Why Do Companies Still Rely On Legacy Systems?

Most organizations keep their legacy systems because of at least one of the following reasons:

  • High migration costs: the IT system is running aging or end-of-life technology that may lack current documentation, making migration complex and, usually, expensive.

  • Skills gap: the technology is supported by “mature” developers with hard-to-find skills, or, in case of migration to another technology, organizations lack enough manpower to focus on the migration while keeping the business running as usual.

  • Fear: legacy systems are often a mission-critical technology, and the organization is afraid of the impact changing it or replacing it can have on the business.

Problems of Keeping Legacy Systems and Why to Modernize Them

Legacy application modernization is often seen as an all-or-nothing approach: you either rip out and replace all the old, legacy technology with something newer or try to make do with what you have, layering new technology onto old to extend its useful lifetime. Afraid of the risks of the first option, most organizations opt for the second, even if it means further technical debt.

Digital transformation fueled by regulatory changes, competition, and the global pandemic has made it imperative for IT executives to find effective ways to modernize legacy systems. To quote Stefan Van Der Zijden, VP Analyst, Gartner:

“For many organizations, legacy systems are seen as holding back the business initiatives and business processes that rely on them. When a tipping point is reached, application leaders must look to application modernization to help remove the obstacles.”

In the digital era, enterprises simply cannot afford to keep aging legacy technology around. Falling into the ‘all-or-nothing’ way of thinking about modernization and only layering newer technology onto old legacy systems only amplifies the problem. This quick-fix approach may work for the short term. However, if it is not done correctly, it will only increase your organization's technical debt.

How to Modernize Legacy Systems

So, how can you modernize your legacy systems without completely disrupting your business way of working and avoiding technical debt?

There are three main approaches you can use:

  • Extend: add new touchpoints and new customer journeys to your system according to your business needs without the risk, cost, or special skills needed for traditional customization of your legacy system.

  • Refactor: transform specific components and create a modular and interoperable architecture that you can change easily at your own pace.

  • Re-build: replace your system with a completely new one built from scratch fully customized to your business needs.

Choosing the Right Approach for Your Business

Organizations must modernize their legacy software applications to add new capabilities, improve user experience, and keep them relevant. The challenges in legacy app modernization still differ according to the type and complexity of the legacy application, business needs and goals, and specific modernization scenarios.

There are different benefits for each approach as well as different challenges. The key is to weigh all options to help identify the extent to which each will have the desired effect, with the minimum effort and maximum positive impact.

To learn more about each approach and when to choose what, download our eBook How to Unlock the Power of Your Existing IT Systems.