Legacy Systems: Definition, Types, Examples and Best Practices

Today’s enterprises typically rely on a large and complex tech stack. There’s likely a wide range of software, hardware, and infrastructure that combines to keep your organization running day-to-day. What’s equally likely is that you don’t regularly update, upgrade, and modernize all of those systems. If that’s true, then you’re likely running what are known as legacy systems. 

What, though, does that really mean, is it a problem and—if so—what can you do about it? Read on to find out. 

What is a legacy system?

A legacy system is any piece of technology (including both software and hardware) that lacks modern features that would be available if you were to update that piece of tech.

This doesn’t mean the system isn’t functional, which is one mistake people make when trying to define legacy systems. Rather, legacy technology often continues to function as it was originally intended

Why are legacy systems still used?

The end of our legacy system definition above helps answer this question. As legacy systems do often still function as originally intended, companies may see little upside in updating them.

Think of the browser you’re reading this article on. If it lets you access the internet, would you spend money updating it even if doing so provided you with some new features?

Businesses use the same logic when it comes to legacy systems, especially as they’re often difficult to replace. 

What is legacy software or a legacy application?

Legacy software, legacy applications, and legacy apps are three other similar terms you may have heard. Are they the same as legacy systems? Well, no, not exactly. As we mentioned earlier, legacy IT systems could be applications or software programs, but they may also be hardware-based. 

In a nutshell, a legacy system is any example of older, outdated infrastructure, whereas legacy software or applications are just one sub-set of that.

Legacy software examples

There are many different possible examples of legacy software. For instance, a legacy operating system like Windows 7 would be considered legacy software, as continuing to use it gives you more limited functionality and support than opting for a newer version. At an enterprise level, meanwhile, you could also describe outdated legacy systems like an on-premises ERP tool as legacy software.

Four types of legacy systems

There are different forms that legacy systems can take. Here are the four common types:

1. End of life (EOL)

An EOL system is one that’s no longer supported by the vendor. These are usually pieces of software that the supplier has improved on, so the original is removed from sale by the developer.

EOL systems don’t receive any updates, leaving them exposed to cybersecurity issues. They’re often incompatible with other pieces of software or hardware as well.

An example of an EOL system is Windows XP, as an older version of Windows it is now seriously outdated.

2. Extensive software patching

Like any technology, software has a limited lifecycle. While lifecycle length can be extended with software patches, systems that are heavily patched can suffer from cybersecurity vulnerabilities.

When software becomes increasingly reliant on patches to run, the chances of a poor-quality patch multiply. That’s why software of this type is also typically described as a legacy system. Where possible, you should always move on from software that’s extensively patched.

3. Outdated system knowledge

Think of technology as a language. If people stop speaking a language, it will soon die out. The same is true of IT systems. As software or hardware becomes outdated, the number of people who are able to effectively work with the technology diminishes.

This means you may end up with only a handful of people in your company who are able to manage a system that’s integral to your organization. Making it another quintessential example of a legacy system.

4. Limited scalability

A piece of technology can also be considered a legacy system if it no longer meets the needs of a business. Even if the system continues to be updated and widely used by other companies, if your specific needs outgrow it, then it will cause the same problems as other legacy systems. 

Companies can outgrow systems if their datasets increase or they expand into a new domain. Software needs to scale with you, or it will become obsolete. If legacy systems are based on physical, on-prem servers, they may also have limited scalability. This is because of the cost of new hardware and the space needed to run it. With inflexible scalability, it can be difficult to meet changing customer or market needs.

Legacy systems examples

Now you know the main types, here are two common and more specific examples of legacy systems:

Legacy financial systems

Fintech is one of the fastest-growing areas of technological innovation, and customers increasingly expect to use mobile apps to perform most banking functions. This rapid rate of change has left many financial services companies relying on outdated software.

With modern technology able to vastly improve customer experience, and heavy regulation within the financial services industry requiring the most up-to-date cybersecurity protection, the downsides of a legacy banking system are clear. 

Legacy database

While legacy financial systems are specific to financial companies, legacy databases can be found across almost every industry. They may refer to data that is stored with outdated software or on an older, monolithic server.

Data is incredibly important, so using a legacy database creates significant challenges for a company. Maintaining an outdated database—often seen for systems that run on mainframe and midrange on-premises systems—can be expensive, and it also risks leaving your data inaccessible if it can’t be integrated with newer technology.

Despite this, many companies shy away from performing a large-scale data migration due to how expensive and stressful the task can be.

Risks of sticking with legacy systems

Choosing to stick with a legacy system comes with some downsides. You might not have access to ongoing support and maintenance due to the age of the technology, and it may gradually lose compatibility with modern formats for the same reason. This might result in you lacking access to new features used by your competitors.

It’s also important to consider the cost of maintaining a legacy system. As these technologies become obsolete over time, businesses can find themselves spending large portions of their IT budget on in-house maintenance. These issues can affect productivity, too.

This means that although it might seem easier to carry on using legacy systems, they can leave your enterprise stuck in the past, failing to keep up with the cutting-edge standards of today’s modern business world.

Despite the benefits, updating legacy systems can be as difficult a task as any other form of digital transformation. As these systems usually form a central part of your business operations, any modernization needs to be well-planned and carefully executed to be successful.

Legacy system modernization

While keeping outdated technology might seem easier temporarily, you’ll soon find that the issues posed by scalability, compatibility, and cybersecurity mean it’s best to modernize.

Here are our best practices for legacy system modernization:

Migrate data systems to the cloud

More and more digital services are becoming centered around the cloud. Rather than being stored on a physical server, which risks becoming outdated and can’t be easily scaled up, data is kept in the cloud instead.

You probably already use the cloud, through applications such as Google Drive, either in your personal or business life. However, when you use it to store your enterprise’s data, you may choose a private cloud platform, which will allow you to optimize settings and costs according to your business needs.

Migrating your data to the cloud brings a range of benefits. Firstly, it means your data can be accessed from anywhere, increasing the flexibility and agility of your company. It can also be easily scaled up without having to worry about investing in new physical storage or memory. Finally, it removes the risk of physical cybersecurity vulnerabilities.

When choosing a cloud provider to store your data, look for a service that can replicate the functions of your legacy system while offering sufficient scalability. Make sure you find a provider with appropriate levels of cybersecurity protection for your industry as well.

Implement a new platform

If you need to replace a monolithic application that’s specifically set up to suit your company’s requirements, you might have to implement a new platform. If you’ve developed your own applications, this can be done internally, although there are also external providers that offer replatforming services.

When implementing a new platform, evaluate which aspects of your legacy system should be maintained as well as which need updating. Take note of any other applications and systems that work with your legacy system so you can ensure their compatibility is future-proofed.

Replatforming will often rely on cloud computing technologies, with newly designed applications running in the cloud. This is a great way to ensure that the integration of your systems and data is supported across your whole enterprise. 

Enhance existing code

One of the ways to deal with legacy systems without having to replatform your operations is by adapting your existing code. This means reprogramming the coding that operates your legacy systems to implement new features or improve compatibility with modern formats.

This will allow you to enhance your legacy software while maintaining its current level of functionality, offering a less disruptive legacy system integration. Streamlining your code will also make your applications easier to maintain.

However, this solution only works in specific circumstances and can’t be applied to third-party software. Furthermore, rewriting existing code can be a time-consuming activity and requires an experienced development team.

Restore the application

Regardless of how you update your legacy systems, you must remember to back up your data so that you’re able to fully restore the application to its original functionality once the legacy system transformation is complete.

Some third-party applications offer restoration automatically, but you should remember to build this into your code if you’re developing a system in-house.

If you’re implementing an entirely new platform, it might be worth restoring specific parts of your legacy code that don’t need replacing. This will allow you to maintain certain continuities between the legacy and the new system while saving your developers time and money.

How OpenLegacy can help you modernize your legacy systems

OpenLegacy offers a modernization solution to bridge the gap between legacy systems and contemporary cloud-native applications. By matching application architecture and natively connecting to core systems, OpenLegacy enables seamless and swift data and process integration that unlocks the potential of businesses’ existing infrastructure.

Legacy modernizatio also provides businesses with the option of a phased or incremental approach to modernization. Instead of undertaking a costly and high-risk system overhaul, legacy system functionalities can be migrated to modern platforms gradually maintaining business continuity.

The parallel running of both legacy and modern systems  minimizes downtime, reduces the risks associated with system failures, and allows organizations to leverage new technologies while preserving their valuable legacy infrastructure investments.

Schedule a demo to find out how OpenLegacy Hub could benefit your business.

FAQs about legacy systems

What does “legacy system” mean?

A legacy system is a piece of technology that is still functional and in use, but is not the most up-to-date form of the system. It is limited in terms of features, support, and more than an alternative which a user could upgrade to.

What is a legacy system in healthcare?

A legacy system is healthcare is a piece of software or hardware still being used in hospitals, clinics, or other medical environments, in spite of more up-to-date alternatives being available. This often happens because those institutions do not have the budget to regularly update systems. 

What’s the meaning of “legacy data”?

Legacy data is information stored within legacy systems. Due to the older nature of the systems, legacy data can often be hard to access and manage but is also often business-critical.

Are legacy systems reliable?

Legacy systems are usually still used by companies because of how reliable they are—although a lack of updates or issues with maintenance means they can quickly become obsolete when things go wrong.

Is Windows a legacy system?

Operating systems that no longer receive updates or developer support, such as Windows 7, Windows XP, and Windows Vista, count as legacy systems.

Why is it necessary to update your legacy system?

Legacy systems should be updated to ensure that you can integrate new applications, access quicker and more reliable technology, and scale up. Doing so will also help you remain compliant with cybersecurity regulations.