Sep 11, 2020 Admin

Software Development

7 Techniques for Successful Legacy System Modernization

Modernizing legacy systems is an absolute must for modern-age businesses to optimize their operational costs, processes, and performance. With new technologies evolving every day, most businesses are trying to figure out the best strategies for modernizing their enterprise software systems and applications. What this means is upgrading existing software systems to boost operational efficiency and productivity. By availing legacy application modernization services, businesses can ease out the steep task of improving their existing systems or applications.

This article below will offer you the best methods that you can stick with while modernizing your legacy systems. Read on: 

Table of Contents

·       Decoding A Legacy System

·       Why Migrating from Legacy Systems is Challenging? 

·       The Business Dilemma: Migrate or Modernize

·       7 Legacy System Modernization Approaches

    • Encapsulation Method
    • Relocation method 
    • Restructuring Method
    • Simple patchwork Method
    • Restructuring Method
    • Rebuilding Method
    • Replacing Method

·       The Golden Advice

Decoding A Legacy System

According to Gartner, a legacy application refers to “an information system that may be based on outdated technologies but is critical to day-to-day operations.” 

The best example of a legacy system is a pager. In the healthcare solutions industry, the use of pager is highly prevalent for communication. Despite being a 90s system and hugely expensive, it is still used. Why? The answer is simple:  it’s hard to replace, especially for critical business processes of the organization.

Apart from healthcare, up to 90% of federal businesses in the US use pager technology. They rely on such legacy systems and keep refining them because it’s critical for their day-to-day operations. Not only healthcare, but legacy systems are used across industries, including banking, transportation, and more for running core business operations. 

Why Migrating from Legacy Systems is Challenging? 

Legacy System Migration Challenges

Upgrading or switching to an entirely new system is part of legacy system modernization. which is often costly and time-consuming for businesses. The other reasons given against legacy modernization are as follows:

Poor operational efficiency 

Businesses argue that legacy migration results in loss of critical business functions, which results in poor operational efficacy and loss in revenue streams. 

Employee Resistance 

Employees get familiarized with legacy systems after working on them for long periods of time and resist change or migration, arguing it will hamper their productivity and waste time. 

Code Compatibility Issues

Handling legacy codes and ensuring the legacy systems complies with new data interchange rules and standards proposed by new client applications is also considered difficult. 

Behavioral Migration Challenge 

Replicating the behaviors of your legacy system in the new system’s infrastructure is costlier and time-consuming. It generally reduces the performance of new systems. 


When multiple systems are part of migration or modernization, prioritizing each based-on time and resources is critical. Simultaneous modernization gives undesirable results. 

The Dilemma: Migrate or Modernize

Here is the daunting question every business face today while going through the path of digital transformation

Which one is a better legacy system modernization or migration? 

Well, the answer simply depends upon your organizational needs. 

If your goal is to abandon a large set of low-value functions or databases, then migration may be the right choice for you. 

On the contrary, if you are looking to boost up the performance of your existing systems like CRM, inventory management software, and more, prefer modernization as it will best suit your goal. 

7 Legacy System Modernization Approaches

Legacy System Modernization

To be frank, techniques for legacy application modernization are increasing drastically, so choose one that best suits your goals. For the best solution, team up with an expert legacy system modernization services provider. 

Each of the below modernization approaches has its own pros and cons, risks, costs, and rewards. The best way to ensure that you meet your goals is to speak with legacy system modernization experts before committing to anyone’s approach.

Encapsulation Method

APIs (application programming interfaces) have been around in business for years but never used as a preferred option for application modernization. But, it’s changing now. By using API solutions, you can simply encapsulate the components of a legacy system and offer it as a service to other enterprise apps or software. For example, building a REST API with universal HTTP connectors for handling multiple legacy systems. It’s the fastest method to resolve interface related concerns. But, it will not solve already existing problems related to upgrading and maintenance in legacy systems.

Rehosting Method 

This technique includes modernizing a legacy system by moving it into a virtual or cloud services infrastructure. This simply means modernizing the current host to make it more reliable, secure, and cost-effective. Re-engineering projects take years, rehosting offers a better solution where underlying business logic remains unhampered. Once the relocation is done, you can run tests to identify lines of code requiring recompiling. 

Restructuring Method 

A decent analogy to explain this method would be replacing cubicles with co-working spaces to facilitate better communication b/w employees. The same concept can be applied in the case of legacy enterprise software solutions where a component is moved into a new runtime environment for better performance. However, minimum changes are done in underlying code structure or features. Here is a technical example: switching from an outdated API to full-service REST API with better security and performance capabilities.

Simple Patchwork Method 

Most A-rated product engineering services firms rely on this method for updating their legacy systems. Here the firms optimize and restructure their legacy systems code without altering its external behavior. Examples include small bug fixes in an app to upgrade its performance and security, eventually leading to overall modernization from scratch. 

Restructuring Method 

As the name suggests, this method includes altering the application code so it can be settled into the new application architecture This is done to explore the fullest capabilities of the new platform. The method is slightly risky, but it offers better results. Most businesses these days focus on shifting from their internal legacy systems by adopting new technologies and making partnerships with expert legacy application modernization solution providers. Investing in a microservices architecture is just a part of this strategy. 

Rebuilding Method 

In case of rebuilding, enterprise software developers rewrite the application code from scratch while safeguarding the underlying system scope and specifications. The reason to proceed with this idea includes opening up doors for integrating new features, functionalities, and processes that are driven by modern technology and third-party platforms. 

Replacing Method 

Many times, replacing the entire legacy system remains the only option in front of businesses. This is because the system becomes too conventional to suit their current goals or operations. While reusing the existing business logic is difficult, some form of reengineering, rewriting of business logic and package customization is applied while opting for this method. 

Legacy System Modernization: Doing it the Right Way 

Hope the above guide has offered you more clarity over legacy system modernization techniques. Well, the key to choose the perfect approach here hides in your in-depth assessment of whether the problem is due to technology, architecture, or functionality of your legacy app. 

And, if you are finding it difficult to rundown your existing system shortcomings and problem areas, consulting with a legacy application modernization services expert like A3logics is never a bad idea. 

With a decade-long experience in the legacy application modernization arena, A3logics delivers personalized enterprise solutions across industries. Our in-house software development teams apply the best techniques to analyze your current legacy systems shortcomings and deliver holistic solutions, truly personalized and efficient.

Drop us a line to consult our experts about your legacy system modernization challenges.

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