Learning Legacy Systems Migration Inside and Out

Companies often cling to legacy systems because they’re familiar—but using outdated technology causes unnecessary expense and leaves you open to security risks. A recent report revealed that 88% of organizations are still hindered by legacy technologies.

As the digital revolution continues, it’s vital for businesses to keep up with technological advancements to maintain efficiency, increase revenue, and stay ahead of the competition. The older your legacy system gets, the more of an obstacle it becomes.

According to the Foundry’s 4th annual Digital Business study 93% of companies have adopted or plan to adopt a digital-first business strategy. But what exactly is involved in swapping legacy systems for modern technology?

In this post, we’ll take a deep dive into the meaning of legacy systems migration, the challenges and benefits to expect, and the potential solutions.

What is legacy systems migration?

A legacy systems migration is when an organization updates an outdated software application by moving it to a new platform, rebuilding it, or replacing it entirely. The aim is to upgrade the original system with modern architecture and technology so that it can meet the expectations of businesses today. For example, a company might migrate from an on-premise system to a cloud platform.

Considering legacy systems migration for your business

If your legacy system is not meeting the needs of today’s online customers, delivers poor performance, needs frequent updates, or is increasingly expensive to maintain, it will have a negative effect on business efficiency as a whole. Legacy systems migration might sound like a no-brainer, but it’s a complex process—there’s a lot to consider before you get started.

You’ll have to weigh up the cost and potential disruption of migration against the continued cost and effort of maintaining a legacy system. And, you must ensure that new tech is compatible with any existing systems and data formats you want to keep. Not to mention - you need to consider how you keep your business running that currently relies on those legacy systems, continue to run smoothly throughout the process.

What is a legacy application?

A legacy application is any system, software, or app built on old or obsolete technology, making it inefficient and costly to maintain. It may no longer be supported by the vendor, or the vendor may no longer even exist.  

Legacy applications can include outdated computer hardware or software. Real-world examples are hardware in power plants, mainframe financial and insurance systems, and manufacturing machines controlled by computers running outdated operating systems.

Such systems can impede your ability to run your business smoothly as well as increase IT costs. For example, if an insurance company wanted to start offering online services, they couldn’t do it without completing an insurance legacy system transformation. 

However, legacy applications are often critical to day-to-day operations. Replacing or adapting them with new technologies is a significant challenge.  

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Importance of legacy systems migration to businesses

Improves technology

The migration of legacy systems to cloud platforms or modern architectures enables you to take advantage of new technologies, such as AI, machine learning, and big data.

You’ll be able to access real-time data from anywhere, get support for a remote working model, and set up automatic backups—none of which are possible with legacy applications. Older systems require downtime to perform upgrades, but new solutions can implement the latest versions of software almost instantly.

Improves performance

After a legacy database migration, you’ll see a significant increase in efficiency and productivity, which means an improved user experience for both employees and customers.

There’s no need to find workarounds for functions that don’t work properly or waste time restarting applications when they crash. Data loading performance is also improved by integrating into the cloud, whereas local storage causes slow loading and potential data loss.

Enhances compatibility and scalability

Legacy applications often cannot connect easily to newer technologies, such as web or mobile interfaces. So, if you do try to integrate any new software into your IT stack, you probably won’t get the full functionality.

But, with a legacy system migration, you’ll have the flexibility to mix and match applications and ensure seamless data flow between them. Plus, cloud-based systems with no physical hardware make it far easier to scale up when needed.

Protects data

Legacy systems might seem like a tried-and-true way to store valuable data, but that’s not the case. As the technology ages, it becomes more vulnerable to breaches, viruses, and data loss—especially if you have a situation where you can’t recover your information should there be a breach.

To handle the latest threats, software requires constant updates and patches. Legacy systems struggle to implement these, but migration or modernization will help to keep you safe. 

Challenges of a legacy system migration

Legacy systems are ingrained into your company’s workflows. Apart from the fear of risk, here are some other challenges involved in rebuilding or replacing them:

Maintenance costs

Modernizing legacy systems normally requires an up-front investment, but you shouldn’t overlook the potential for ongoing costs as well. For example, the price of buying cloud capacity might outweigh the benefits, and you need to check that the vendor has a transparent pricing model.

Another hidden cost is maintenance. For instance, if you use ESB (enterprise service bus) and middleware to connect old and new apps, you’ll have to factor in the cost of training, engineers, monitoring, and patch management.

Security risks

Your existing systems will have been modified many times over the years, creating a patchwork of fixes that were implemented each time a security issue or other modification was identified. If these instances were not well documented at the time, it’s possible that the migration project could re-expose you to the risks.

In addition, it might not be possible to automate every aspect of the migration, which means data will need to be entered or modified manually. This can lead to more issues due to human error and the time-consuming nature of the task.

Data audit for users

Apart from the security issues, data migration from legacy systems is a complex process and a resource-intensive task. It requires an audit to evaluate the state of the data, determine how much of it needs to be migrated, and in what format it should be post-migration.

Migration requires high data protection measures, and it’s not uncommon for data to become corrupted or lost during the process. You’ll need to make a backup of your data and put a disaster recovery plan in place.

Software conformity

Your legacy system migration will also run into problems if your existing software is incompatible with the new system. This is particularly likely if you created custom integration solutions as workarounds to extend the life of the legacy application.

It’s also possible that you’ve lost track of all the applications that integrate with an old system. You’ll need to categorize all the elements, especially the custom ones, and ensure that you find a workable solution before the data migration takes place.

Software license use

Don’t forget that your new system might need a new license enabling you to purchase or remove some software. When you migrate to a new system over time, there may be an unavoidable period of overlap between the previous software license and the new one—incurring extra costs.

It’s best to pick software platforms that can be deployed on any of the major clouds, as they’re typically available with quick installation and cloud licenses.

Hardware compatibility

If you can find a cloud solution that’s compatible with your existing system hardware, you can reduce the cost of the migration. But, if the legacy system is particularly super-old, that’s harder to do—meaning you’ll have to replace the hardware as well.

Meanwhile, your software apps may be dependent on a particular OS, which can only run on a certain version of hardware. If vendor support for that hardware has ceased, you must check that the app can run on an upgraded platform.

Complex Legacy Ecosystems

Even straightforward migrations may involve deeply intertwined applications and databases—making “lift-and-shift” more complex than it appears.  Some systems are so tightly coupled that migrating a single component without modernizing or refactoring may cause downtime or performance issues if not identified and planned to be done before any migration even starts - often delaying project lines significantly.

Legacy system migration types

There are a couple of different ways to carry out a legacy system migration. The best choice for your business will depend on your legacy system and your wider digital transformation goals. The seven most commonly used legacy modernization approaches are:

1. Replacing involves abandoning your older system entirely and replacing it with a new solution. This method is the most intensive in terms of data migration and system onboarding.
2. Replatforming is the process of porting an application’s components to a new platform. Using an API integration platform allows developers to adapt applications to the new platform with minimal code changes. This method also lets businesses keep their tech ecosystem while benefiting from modern solutions.
3. Also known as lift and shift, rehosting is when a system and its data are migrated to a cloud platform without making significant changes to the application architecture. Simply copying everything to the cloud is a quick migration method that is useful for addressing technical bottlenecks in IT operational activities.

There are a couple of different ways to carry out a legacy system migration, and your choice will depend on how comprehensive you want the migration to be.

Lift and shift migration

This method is also known as rehosting. It’s when you migrate your system and its data to a cloud platform without making significant changes to the application architecture. By simply copying everything to the cloud, you avoid the time and expense of a full business transformation.

Typically, you’d choose a lift and shift migration to address a technical bottleneck in IT operational activities, rather than a problem that’s affecting the whole business.

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1. Refactoring involves adding new technologies to your business systems, for example, connecting legacy system components to cloud-based environments using code changes. While it is less disruptive than a complete replacement or rewrite, refactoring requires heavy technical work from experienced engineers.
2. Rebuilding allows businesses to start from scratch. Although building a new enterprise system is disruptive and expensive, it can result in the most significant benefits for your organization.
3. Rearchitecting accesses new platform capabilities through the use of new application architecture. An example would be migrating your legacy system from your internal infrastructure to a modern alternative to access real-time data streams. 
4. (W)Rapping is also known as encapsulation. This method of migration benefits from rapid deployment and minimal code changes by using APIs to create access layers for existing legacy components. 

Business transformation

If your legacy system is causing wider inefficiencies, a business transformation is the more complete option. For instance, you might want to swap monolithic software architecture for a more scalable solution. This type of migration requires rebuilding or replacing the original system. It’s likely to have a bigger upfront cost, but with lift and shift you’ll be paying ongoing fees to the host.

Use a legacy system migration strategy to reduce risk

What is a migration strategy?

A migration strategy for legacy systems is a comprehensive plan created by organizations before they transition from older systems to new technologies, for example, the cloud. Typically, the strategy will aim to identify and mitigate risks, minimize disruptions, and maximize the benefits of the migration. A successful migration strategy can be used as a roadmap to guide and support teams throughout the entire legacy systems migration process.

A six-step legacy system migration strategy example

While your exact legacy migration strategy might vary depending on your exact situation and needs, this six-step example can provide a good base for a safe legacy system modernization.

1. Assess and analyze: The first step in any legacy migration strategy needs to involve a thorough appraisal of your current systems as well as your business goals. This will allow you to position your legacy system migration within your wider digital transformation strategy. The analysis of your legacy systems will also give you a thorough understanding of the data and applications that need to be migrated.  
2. Choose a migration type: We explored the different types of legacy migrations earlier in this article. The best one for you to choose will depend on the results of your previous analysis. The migration type you select should help you to meet your business goals and allow you to preserve the vital functionalities of your legacy systems.
3. Conduct contingency planning: We also highlighted the challenges of legacy system migration earlier, any of which could lead to an unfortunate waste of time, budget, and resources. Consider how any of these risks could affect your planned system migration strategy. Planning for the worst-case scenario should allow you to avoid them. This stage should also involve completing a thorough backup of all your data.
4. Prepare the new environment: It’s vital to prepare your legacy systems for migration, but, as with any type of movement, you need to make sure your landing pad is also ready. Carefully check the compatibility of all your legacy system applications and databases, as well as the suitability of any cloud platform you might have chosen. Extra checks at this stage can save you from potentially disastrous data loss in the future.  
5. Pilot migration testing: After these steps, you’re nearly ready for your legacy system migration. It’s worthwhile running a test migration at this point. Although it takes time and effort to conduct user, performance, and software testing, it’s much better to discover code or system bugs that could negatively affect your migration in a controlled environment. 
6. Implementation and validation: Once you’ve removed any bugs that could cause application downtime, you can proceed to your real migration. Completing this in stages will allow you to keep testing, validating, and backing up your data throughout the process for continuous security and refinement.

Facilitate your business’s legacy systems migration seamlessly with OpenLegacy

OpenLegacy is a cloud-native platform for legacy modernization, designed to build bridges between your old and new systems. You can easily standardize, reuse, or create digital services to meet modern business needs, while reducing the complexity, time, cost, and risk of a migration.

Our hybrid integrations strategy makes the legacy systems migration process as smooth as possible, quickly generating and deploying digital services from legacy assets with no changes or special skills required. You can manage those services as cloud-native applications and deploy them to any cloud or hybrid cloud.

No matter whether you’re modernizing in place, replatforming, or replacing the entire legacy application, OpenLegacy meets all the challenges we discussed earlier. It connects directly to on-premises legacy and core systems. OpenLegacy automatically generates digital-ready code and deploys it as standard microservices or serverless functions. Continuous development means your mission-critical systems remain stable—and with reduced reliance on ESB middleware, overall costs and maintenance are lower. 

FAQs on legacy systems migration

How do you modernize a legacy system?

Modernization is the process of updating, migrating, or optimizing legacy systems to work with modern technology. This may include rehosting applications in the cloud or switching from a monolithic system to microservices. If your current system is expensive, no longer able to meet business needs or a security risk, modernization could help. Create a legacy system migration strategy that includes evaluation of your legacy system, identification of your business and modernization objectives, selection of a modernization type, and risk assessments. Modernization is the process of updating, migrating, or optimizing a legacy system to include modern platform infrastructure, architecture, and features. This may include rehosting applications in the cloud, using containers or Kubernetes, or switching to microservices instead of monolithic systems.

Start by evaluating your legacy system to see how it measures up in terms of flexibility, cost, and risk. If it’s too expensive, no longer able to meet business needs, or poses a security risk, you can take the decision to modernize. Define the nature of these problems and set your objectives.

There may be elements of the system that still work well, so decide what you want to keep. Then choose a modernization strategy based on timeframe, cost, security, and scalability—ensuring that it will meet your company’s future needs. Your choices are as follows:

• Retain/encapsulate (retain or reuse components within a new architecture)
• Rehost (“lift and shift” application components to other infrastructure)
• Replatform (move the existing code to a new platform)
• Refactor (optimize the code and make changes to its structure)
• Re Architect (significantly alter the code to shift it to a new architecture)
• Rebuild (redesign or rewrite the application from scratch)
• Replace (find a completely new product).

Whichever option is right for you, make sure you choose the right partner to help you through the modernization process. And, while the transition is in progress, carry out iterative testing to spot any problems with hosting, software licensing, or connectivity to other services.

What are the limitations of legacy systems?

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There are many limitations to using legacy systems. They’re often unable to run or integrate the latest software programs, leading to low efficiency, poor connectivity, and a lack of data flow visibility as well as gifting competitors an opportunity to modernize and get ahead. Outdated systems also lack stability and are prone to failures and outages, which hinder staff productivity and result in downtime. As maintenance costs for legacy systems are higher, these outages can be costly as well as inconvenient. Furthermore, vendors can discontinue support for legacy systems, which can lead to security issues. There are many limitations to legacy systems, including low efficiency, poor connectivity, and a lack of visibility into data flows.

They’re often unable to run or integrate the latest software programs unless you can find a workaround—and the need for manual intervention takes time and costs money. Meanwhile, you’re stuck with redundant features or functions that don’t do what they’re supposed to.

As legacy systems get older, the maintenance costs get higher, and there are fewer people with the skill set to manage them. Vendor support may become obsolete, which means you won’t automatically receive updates and bug fixes. This leads to security issues, leaving you at risk of malware attacks.

Outdated systems also lack stability and are prone to failures and outages, causing disruption to the business. As well as hindering staff productivity, this provides a bad user experience for customers, which can damage your company’s reputation.

Are legacy systems flexible?

In a word, no. Legacy systems suffer from inherent inflexibility, which makes them difficult or even impossible to adapt or customize. Your existing system may not be able to handle any changes in your workflow and processes and. It probably won’t be able to connect to new applications or let you access data from mobile devices. Because of this, legacy systems are holding many companies back. However, legacy systems migration allows you to use upgraded or replacement solutions that can provide almost endless flexibility.

Because legacy systems can’t keep up with the pace of technological change or adapt to the modern business environment, they are holding many companies back. For example, if you wanted to start offering online insurance services to your customers, you couldn’t do it without an insurance legacy system transformation.

Legacy systems migration gives you almost endless flexibility. Your upgraded or replacement solution will be able to handle updates, integrate with other applications, and adapt to process changes without disrupting your business operations.