Legacy Application Modernization: Complete Breakdown

Legacy applications are the backbone of many organizations today. These older software systems continue to run critical business processes for companies across various industries. While legacy applications are stable and reliable, they can constrain businesses due to issues like lack of agility, mounting maintenance costs, and limited integrations.

In this blog post, we’ll provide you with a comprehensive understanding of legacy application modernization. We’ll explore what it entails, when the right time to modernize is, and what to expect throughout the process. We’ll also look at seven strategies for modernizing legacy applications and guide you in selecting the right approach for your business.


What is a Legacy System?

A legacy system may refer to an outdated software that is still in use within an organization. These systems have been in operation for years or even decades and often rely on older technologies, programming languages, and architectures. Despite the emergence of modern technologies, legacy systems continue to play an important role in many industries.

One example of legacy systems are IBM i applications which gained popularity due to its platform’s robustness, reliability, and scalability. Industries such as manufacturing, finance, distribution, and healthcare heavily rely on IBM i applications to support their critical business processes. These applications have proven their stability and continue to provide value to organizations, even though some of them are decades old.


What is Legacy Application Modernization?

Legacy modernization is the process of transforming and updating legacy applications to modern architectures, technologies, and platforms. The goal of modernization is to improve the functionality, performance, and user experience of the application while reducing costs and minimizing risks.

While legacy systems have proven their reliability through years or decades of service, there are a number of challenges associated with them, including:

  • Technical complexity: Many legacy systems have been heavily customized or extended to meet specific business needs. These customizations can add complexity, especially if they were poorly implemented.
  • Lack of documentation: As time goes on, the knowledge about the application and its intricacies may be lost as experienced developers retire or move on to other projects, leaving new developers with the challenge of understanding a complex system with limited guidance.
  • Skills shortage: Legacy applications are typically built using older programming languages, frameworks, and technologies that are no longer in widespread use. This makes it difficult to find developers with expertise in these technologies.
  • Cost: Maintaining and supporting legacy systems can be costly due to the need to find and retain specialized talent, source replacement parts, and deal with hardware and software issues. In the long run, it can add up to be much more than the cost of modernization.


Why Modernize Legacy Applications?

It is important to understand that modernizing legacy applications does not mean replacing them entirely. Replacing legacy applications can be risky, costly, and time-consuming. Legacy software modernization means transforming them into modern systems that can leverage existing business logic and data while enhancing the functionality and usability of the systems.

One example of a legacy system that is worth modernizing rather than replacing is the IBM i. IBM i applications are still widely used by many businesses because they are stable and reliable and support a wide range of functions. Modernizing an IBM i application can:


When it’s the Right Time to Modernize?

There are certain signals that indicate it may be time to modernize legacy systems:

  • The inability to meet new business requirements due to legacy limitations
  • Rising maintenance costs
  • Struggles to find staff with the right skills to maintain legacy technologies
  • The need for integration with other modern systems
  • The desire to improve agility, customer experience, and competitive advantage
  • Growth plans that required scalability that’s not possible with a legacy infrastructure
  • Security and compliance risks posed by unpatched, older systems

If legacy systems start impeding business progress rather than enabling it, that is usually a clear sign that modernization should become a priority. At that point, the costs of not modernizing outweigh the short-term effort and disruption involved.


Benefits of Modernizing Legacy Applications: What to expect

Legacy system modernization delivers tangible business results. Here are some of the benefits it can bring your business:

  • Cost savings: A study by IBM found that organizations that modernize their legacy applications can see 15-35% savings yearly on infrastructure, a 30-50% reduction in application maintenance and running costs, and a 74% reduction in costs on hardware, software, and staff. [1]
  • Improved efficiency: Modernizing legacy applications can improve their performance, scalability, and reliability so that they can handle increased workload, process data faster, and recover from failures quicker.
  • Enhanced security: Modernizing legacy applications can protect data and transactions from cyberattacks, data breaches, and unauthorized access as well as bring them up to date with regulations like GDPR, PCI, or HIPAA.
  • Increased agility and innovation: By replacing outdated technologies with modern, flexible architectures, organizations can iterate faster, experiment with new features, and respond promptly to customer demands.
  • Better integration and collaboration: DSI improved its supply chain visibility and collaboration by modernizing its legacy applications using EDI and other modern technologies.


Legacy Modernization Technologies

Legacy application modernization involves leveraging various technological advancements to transform and enhance existing systems. Here are some of the key technologies that play an important role in modernizing legacy applications:


Migrating legacy systems to private or public cloud environments provides increased scalability, flexibility, and potential cost savings from not needing to maintain on-prem infrastructure. Cloud-native features can be added to expose services for mobile and web. Cloud also enables easier disaster recovery capabilities for legacy systems.


Container technologies allow legacy codebases to be containerized and deployed on modern container orchestration platforms. This brings greater portability and improved resource utilization to legacy applications, providing automatic scaling and load-balancing capabilities to legacy workloads.


Monolithic legacy applications can be broken down into independent microservices by refactoring them into modular components with well-defined interfaces. This allows modernization to be done in stages by building new microservices that connect with legacy systems. Microservices make legacy applications more resilient, scalable, and easier to maintain.

Orchestration and Automation

IT process automation through orchestration tools helps streamline deploying upgrades, configurations, and new features for legacy systems. Automating these processes gives IT teams more time to focus on tasks that truly add value.


Adopting DevOps practices and continuous delivery pipelines brings more agility to legacy system changes. Continuous integration and automated testing replace manual, error-prone software releases. This allows for faster, more reliable updates to legacy applications.


APIs enable simple integration of legacy systems with modern applications, devices, and cloud services. APIs abstract away legacy complexity and provide standard integration mechanisms.

.NET Solutions

Solutions like LANSA Open for .NET give Windows developers the ability to access IBM i data and software directly from their .NET applications, offering easy integration between IBM i and .NET.


The Role of APIs in Legacy Application Modernization

APIs play a pivotal role in modernizing legacy systems by enabling integration with modern technologies. APIs act as a bridge, allowing legacy software to securely expose functionality and data to other applications and devices. For example, adding REST APIs to legacy systems like IBM i allows for developing mobile apps, leveraging cloud services, and adopting microservices architecture.

APIs abstract away complex legacy code and provide standard modern interfaces for other systems to consume. Well-designed APIs minimize the need for refactoring. Companies use API-led integration to incorporate Innovations like IoT, AI/ML, and real-time analytics into legacy environments. They unlock legacy system capabilities without compromising security or reliability.


Legacy Modernization Steps

Modernizing a legacy application is a multifaceted process that involves several key steps to ensure a successful transformation. While every modernization journey is unique, most follow a similar high-level path:

Step 1: Evaluate your Legacy System

Assess the strengths, weaknesses, and limitations of your existing legacy system. Gain an understanding of its underlying technologies, dependencies, and complexities. This evaluation process will provide valuable insights into the areas that require Improvement and help guide your modernization strategy.

Step 2: Define the Problems

Identify the specific pain points and challenges that your legacy application is currently facing. Are there performance bottlenecks, scalability issues, or outdated user interfaces? Define the problems you aim to address through modernization. This step sets the foundation for determining the most suitable modernization approach and selecting the right technologies and tools.

Step 3: Legacy Application Modernization Strategies: Choose the right one

There are quite a few strategies available for legacy application modernization. Each strategy offers a unique approach to transforming the existing system. Consider the following strategies and choose the one that aligns with your business goals and requirements:


Encapsulation involves wrapping the legacy application in a modern framework or environment without making significant changes to the underlying code. This approach provides limited modernization benefits but can offer quick wins in terms of improved user experience and accessibility.


Replatforming means making minimal modifications to the legacy application to take advantage of modern platforms and technologies. It may involve migrating to a newer version of the operating system, database, or development framework. Replatforming offers a balance between cost-effectiveness and modernization benefits.


When rehosting an application, you’re moving it to a fresh environment without making any major changes. This is often one of the quicker and less expensive modernization options. Once you’ve migrated the app, you can take advantage of a more efficient and flexible infrastructure.


Refactoring requires making significant code-level changes to improve the structure, design, and performance of the legacy application. This approach focuses on enhancing maintainability, scalability, and extensibility while preserving the core business functionalities.


When replacing an application, you completely discard the legacy app and build a totally new solution. In some cases, you have no choice but to replace it because your legacy app will never be compatible with an important software or system your business needs.


Rearchitecting necessitates redesigning the entire application architecture to adopt modern architectural patterns, such as microservices or service-oriented architecture. This strategy enables organizations to achieve greater flexibility, scalability, and agility in their application landscape.


Rebuilding entails rewriting the legacy application from scratch while retaining its core functionalities and business logic. This approach offers the highest level of modernization benefits but requires substantial resources and the most time.

Explore our guide on application modernization strategies.

Step 4: Prepare for Future Growth

As you modernize your legacy application, it’s important to think of the future and how much you plan on growing and scaling the system. Ensure that the modernization efforts align with your long-term business goals and accommodate evolving technology trends. Future-proof your application by designing it to be flexible, modular, and easily adaptable to changing requirements.

Step 5: Choose the Right Modernization Solution

Selecting the right modernization solution is important for a successful legacy application transformation. Consider factors such as the complexity of your legacy system, the desired level of modernization, available resources, and the skills of your development team. Evaluate modernization tools, frameworks, and platforms to find those that best fit your business requirements.

Step 6: Observe and Optimize

Once the modernization process is complete, continue to monitor and optimize your modernized application. Collect feedback from users and stakeholders to identify areas that you can improve. Regularly assess the performance, scalability, and security of your new infrastructure to ensure that it is performing as expected.


How to Select the Best Mondernization Approach

Determining the best way to modernize a legacy application is not a one-size-fits-all decision. However, here are the factors you should consider when you are deciding which modernization strategy to use:

  • Risk: Assess the business risks involved in modernizing your legacy application and choose the approach that minimizes them.
  • Scope: Once you identify the features that need to be modernized in your current system, you’ll be better equipped to choose the right approach to add them.
  • Architecture: Both your current infrastructure and the architecture of new features will help you determine the best strategy.
  • Operations: Compare the new skills your team will need to use the modernized systems and the training they will need to your existing processes.
  • Security: The approach you choose should prevent data loss before, during, and after the modernization process as well as comply with any governmental or industry regulations.
  • Cost: Calculate your budget and spend wisely. Your budget will be one of the largest factors that help determine which approach to take.


Challenges of Legacy Modernization

Legacy application modernization is not a simple or straightforward process. It involves many challenges that organizations may face along the way. Here are some of the common challenges, along with some tips to help overcome them:

  • Resistance to change: Communicate the benefits and goals of modernization clearly and frequently. Involve and engage the users in the modernization process and provide them with adequate training and support.
  • Lack of skills: Invest in training, hiring, or outsourcing to acquire the necessary skills for modernization. Retain and reward the existing staff who have valuable knowledge and experience with the legacy systems.
  • High costs: Calculate the return on investment (ROI) of modernization. Compare the costs and benefits of different modernization approaches and choose the best fit.
  • Complexity: Conduct an assessment of the legacy applications’s architecture and leverage tools that assist in refactoring and code remediation. Break the modernization process into smaller, manageable tasks to make changes incrementally.


Questions to Ask Before Modernizing

Before undertaking any legacy modernization initiative, key considerations should be evaluated through targeted questions like:

  • What pain points are the legacy applications causing for the business and customers?
  • How would a modernized application better meet current and future needs?
  • Which capabilities are top modernization priorities: mobility, cloud, analytics, etc.?
  • What is the desired timeline based on business drivers?
  • What integration capabilities are required with other systems?
  • What regulatory and compliance requirements must be met?
  • What skill sets are available internally vs. needing external partners?
  • What risks need mitigation strategies?


Successful Case Studies

Legacy software modernization has proven to be beneficial for many organizations across a wide variety of industries. Here are some examples of how they achieved their modernization goals and improved their business outcomes:

The Museum of Modern Art – Modernizing Membership Management and Ticket Verification

The Museum of Modern Art successfully modernized its legacy system using LANSA. They implemented an integrated Windows and web-based membership management system, as well as a point-of-sale solution for ticket verification using wireless PDAs. This transformation enabled MoMA to streamline its operations, improve productivity, and improve the visitor experience.

Read case study

Kawasaki – Revolutionizing Warehouse Management

Kawasaki, a leading manufacturer of motorcycles and heavy equipment, leveraged LANSA to modernize its warehouse management system. Kawasaki needed a set of mobile apps for the iPad that could integrate with the corporate ERP system and access an external scanner. Using LANSA LongRange, they were able to develop the apps in-house and saved $3,500 per day in labor and safer assembly lines.

Read case study

Braum’s Ice Cream and Dairy Stores – Enhancing Mobile App Capabilities

Braum’s, one of the world’s largest dairy operations, used LANSA to enhance their mobile app capabilities. The company’s district and area managers gained real-time access to critical business reports, which allowed them to make informed decisions on the go. LANSA also facilitated the revamp of Braum’s maintenance system, resulting in streamlined inventory management and cost savings.

Read case study

Top Trends in Legacy Application Modernization

Legacy application modernization is continuously evolving to meet the demands of the digital age. As organizations strive for digital transformation and improved agility, several emerging trends and technologies are shaping the future of modernization efforts, including:

  • Cloud-native architecture: Cloud technologies like serverless are gaining traction in modernization and provide scalability and flexibility.
  • Low-code/no-code development: These development platforms can abstract complex coding tasks and enable rapid application development without extensive programming expertise.
  • AI/ML: Artificial intelligence and machine learning are being used to automate many tasks involved in legacy application modernization, such as code analysis, dependency mapping, and impact assessment.
  • DevOps: Modern DevOps practices like containerization and orchestration are making legacy applications more scalable and resilient.


Don’t Wait Long to Get Started

Legacy application modernization will transform your legacy systems to meet the demands of the digital age. It can improve the performance, scalability, security, and user experiences of your business software as well as enable new digital business models and improve compliance with industry and government regulations.

Modernization is important for long-term success because legacy software can become a burden on organizations. Legacy applications can be expensive to maintain, difficult to integrate with other systems, and vulnerable to security threats, but with the right modernization approach, legacy systems can help propel business growth rather than hold it back.

LANSA’s comprehensive suite of modernization tools empowers businesses to transform their IBM i applications efficiently and within budget. To learn more about LANSA’s IBM i modernization solutions, visit our IBM i modernization page. If you’re ready to start the modernization process or have any questions, please contact us so we can guide you through the process.



[1] https://www.ibm.com/blog/four-steps-to-app-modernization-success/

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