What is COBOL modernization? 

COBOL modernization refers to the process of updating and improving COBOL-based systems, which are often legacy applications critical to the operations of an organization. This can involve migrating the systems to new platforms, integrating them with modern software architectures, or rewriting them in more contemporary programming languages. 

The goal is to retain the valuable business logic embedded in COBOL applications while enhancing their performance, security, and ability to integrate with newer technologies.

The modernization process varies significantly among projects but typically aims at making COBOL applications more adaptable and easier to maintain. 

By applying modern development practices and technologies, organizations can overcome the limitations imposed by outdated infrastructure. This ensures that critical applications continue to support business needs without risking system failure due to obsolete technology.

This is part  of a series of articles about legacy code

Why consider COBOL modernization? 

There are several reasons that an organization might consider modernizing their COBOL applications:

  • Integration with modern systems: This allows legacy applications to communicate and operate seamlessly with newer, more advanced technologies. It retains the processing power and reliability of COBOL applications while taking advantage of the flexibility, scalability, and enhanced security features offered by the latest software frameworks and cloud services.
  • Cost efficiency: By updating legacy COBOL systems, organizations can reduce the expenses associated with maintaining outdated hardware and software. Modern platforms and technologies often offer better performance at a lower operational cost due to improved efficiency and reduced resource consumption. Additionally, modernized applications tend to require less manual intervention for maintenance.
  • Enhanced features and capabilities: Modernized COBOL systems can better support integration with technologies like cloud computing, big data analytics, and artificial intelligence. Previously unattainable with legacy systems, these features improve scalability and allow companies to implement advanced security measures. 
  • Regulatory and compliance pressures: Organizations operating in highly regulated industries must comply with evolving legal and regulatory standards. New regulations often require more sophisticated data processing capabilities, enhanced security measures, and detailed reporting functionalities that legacy COBOL systems cannot support without significant modifications.

The difficulties of modernizing COBOL applications

There are several challenges involved in modernizing COBOL-based systems.

Legacy codebase complexity 

COBOL applications, particularly those that have been operational for decades, often have a complex legacy codebase. This complexity stems from years of accumulated code, where different programmers have made contributions in varying styles, leading to inconsistencies and a lack of standardization. 

The sheer volume of code, coupled with outdated practices and sometimes the absence of documentation, challenges modern developers tasked with understanding and modifying these systems. To add to the complexity, legacy COBOL applications often contain business logic and processes intricately woven into the code.  

Lack of skilled developers 

As the tech industry evolves, newer programming languages and technologies become more attractive to the emerging workforce, leading to a scarcity of skilled COBOL programmers. This gap in expertise makes it difficult for organizations to maintain, troubleshoot, and update their legacy COBOL applications.

The lack of developers familiar with COBOL also exacerbates the risk associated with modernizing these applications. Without sufficient knowledge and experience, attempts to modify or integrate legacy systems can introduce errors or lead to system failures.  

Minimal documentation 

As developers and employees leave organizations, they often take with them critical knowledge about the applications’ design and functionality. This loss of institutional memory makes it challenging for new developers to understand the intricacies of the application, including its business logic and data structures, which are essential for integration with new systems.

Without adequate documentation, it becomes difficult to diagnose issues, implement new features, or ensure compatibility with modern platforms. Developers must reverse-engineer applications to understand their functionality. 

Integration with legacy systems 

Integrating COBOL applications with legacy systems involves navigating outdated protocols and data types. This challenge is compounded by the need to maintain uninterrupted operations across interconnected systems. Integration strategies often require custom adapters and middleware, which enable communication between COBOL applications and other legacy technologies. 

These solutions must be carefully designed to ensure data integrity and system stability, avoiding disruptions to critical business processes. The integration process must also account for the performance limitations of older hardware and software. For example, optimizing data exchange and processing to minimize latency.

5 Critical COBOL modernization techniques

Here are some of the tools and techniques that organizations can use to overcome the challenges of modernizing their COBOL applications.

1. Code refactoring 

Code refactoring involves the systematic revision of existing code to improve its structure and clarity while maintaining its functionality. It helps address the challenges posed by legacy COBOL applications, such as complex codebases and outdated programming constructs. 

By refactoring code, developers can simplify complex sections, remove redundancies, and update obsolete syntax to adhere to modern standards. This makes the code easier to understand and maintain, preparing the application for integration with new technologies. Refactoring can also enhance the performance and scalability of COBOL applications.  

Learn more in our detailed guide to legacy code refactoring 

2. Automated code conversion 

Automated code conversion tools translate legacy code into modern programming languages. They analyze the COBOL source code, identify its structures and logic, and generate equivalent code in a target language such as Java or C#. This process reduces the time and effort required to modernize applications.

However, automated conversion requires careful preparation, including cleaning up the source code and ensuring that it adheres to best practices for a successful translation. Post-conversion, manual intervention is often necessary to optimize the generated code for performance, readability, and compatibility with modern development environments.  

3. Business rule extraction

Business rule extraction involves identifying and isolating the business logic embedded within legacy COBOL applications. This includes analyzing the source code to pinpoint specific rules and algorithms that define business operations. Once extracted, these rules can be documented, optimized, and then re-implemented or integrated into modern systems. 

This approach ensures that critical business logic is preserved during the modernization process. By focusing on the business logic, companies can prioritize which aspects of their legacy applications need updating or integration with new technologies. This can lead to more efficient use of resources and a smoother transition to modern platforms. 

4. Modular modernization approach 

A modular or phased approach to COBOL modernization breaks down the process into manageable segments, allowing for incremental improvements. This enables organizations to tackle specific areas of their system without the need to overhaul the entire application at once. They can test and validate changes without disrupting operations. 

With this approach, each segment can be updated and optimized independently before being reassembled into a cohesive system. As each module is modernized, it can immediately start delivering benefits in terms of performance, security, and compatibility with new technologies.  

5. Creating documentation

Creating documentation for COBOL modernization involves systematically recording the structure, functionality, and business logic of existing COBOL applications. This documentation serves as a roadmap for developers, simplifying the modernization process by providing clear insights into application workflows and dependencies. 

It also aids in knowledge transfer, ensuring that valuable information about legacy systems is preserved and accessible to new team members. By understanding the COBOL applications, developers can make informed decisions about how to refactor or integrate them into new environments. 

Documenting legacy code with Swimm

Legacy code represents a significant challenge as well as an opportunity for software organizations. Managing legacy code entails more than just dealing with untidy or outdated code; it involves transforming it into a reliable and efficient foundation that supports future development initiatives. Handling legacy code effectively can lead to considerable long-term savings and heightened productivity, marking it as a strategic priority for any R&D organization. 

Swimm is a devtool that will help you and your team document legacy code in an easy, manageable, and effective way. Utilize AI to create docs about legacy code and then discover those docs directly in your IDE. Those docs then stay up to date with ongoing code changes, boosting your team’s productivity and enhancing the quality of your codebase.