Mainframes still play a critical role in many organizations, yet as digital technologies have evolved, maintaining these legacy systems has become increasingly challenging. By modernizing mainframe systems, companies can save money, increase agility, and reduce risk.

In this article, we’ll explore the question of why organizations are modernizing, the challenges of staying on the mainframe, and recent innovations that are making it faster, easier, and cheaper than ever to modernize.

The ABC’s (and D’s) of Mainframe Modernization

What’s driving change? Why are so many IT leaders finally making the decision to migrate their mainframe workloads?

Mainframe systems typically handle an organization’s most mission-critical transactions. They tend to be complex, and they often rely on legacy code that isn’t very well documented. Not surprisingly, many CIOs are cautious about launching modernization initiatives. After all, these are big projects, and they need to be done right. Yet for most organizations, the status quo is the riskiest path of all.

Let’s explore the factors that are driving more and more organizations to forge ahead with modernization projects:

AGILITY:  In today’s hyper competitive global economy, first-mover status matters. In virtually every industry, digital transformation has become the key driver of innovation, differentiation, and business value. Cloud computing provides the foundation for this change, yet legacy mainframe systems are often difficult to integrate with advanced analytics, mobile apps, IoT devices, and other modern technologies. Hierarchical databases, procedural code, and waterfall methodologies stand in the way of rapid innovation. Mainframe modernization breaks down those barriers and opens the door to greater organizational agility.

BRAIN DRAIN: Organizations that run these legacy systems are finding it more and more difficult to hire and retain experienced mainframe engineers. As a generation of skilled specialists reaches retirement age, very few new college graduates are stepping in to replace them. The COVID pandemic made this problem even worse, prompting many to retire early. The talent shortage will undoubtedly grow even more acute in the coming years.

COST: Mainframe customers have seen steady increases in operating costs over the past few years. As the number of companies running mainframe systems dwindles, economies of scale will dictate that prices increase even further. By migrating their workloads to the cloud, companies can save as much as 90% on annual operating costs.

DECOMMISSIONING: In some cases, organizations choose to modernize because they simply have no other path forward. If their old Unisys mainframe has reached the end of its useful life, for example, they simply have no choice but to modernize.

The Road Ahead: Mapping Your Modernization Journey

As with any large-scale project, it’s critically important to assess your current environment and evaluate various options before you commit to a specific path. Some companies prefer to modernize on the mainframe, whereas others prefer re-platforming or re-factoring.

With over three decades of experience in mainframe modernization, Astadia helps our clients evaluate their current systems, determine the approach that best fits their needs, and build consensus around a mainframe modernization plan.


An essential part of any mainframe migration project is the assessment phase. Thoroughly evaluate your existing mainframe environment, including hardware, software, applications, and data. Understand the technical debt and operational limitations. This can give an overview of the project scope and help align the modernization project with overarching business goals. Whether it's improving performance, reducing costs, or enabling new capabilities, we help you to clarify how modernization supports these aims.

Many of our clients choose to start with a FastTrack Mainframe Assessment, in which we create a clear picture of where you are today. This is a discovery process in which we inventory your existing applications, identify risks and dependencies between various applications and databases, build a roadmap to your target platform, and develop a plan for project success.


Decide on the modernization approach—rehosting, replatforming, refactoring, rewriting, or replacing. Each has different implications for cost, risk, and business impact and involves choosing the technologies for the new environment, including cloud platforms, databases, and application architectures. At this stage, organizations should also consider compatibility, scalability, performance, and vendor support.

Based on the selected approach, the project team can already identify potential risks, including technical, operational, and financial risks, and develop mitigation strategies for each identified risk.


Establish a budget that covers all aspects of the modernization project, including software, hardware, training, and contingency costs.

Form a project team with roles clearly defined Include internal IT staff and experienced mainframe modernization experts. Plan for potential training and up skilling of staff to handle new technologies and processes.

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Develop a realistic timeline for the project, with key milestones and deadlines. This will largely vary for organizations choosing between a phased approach or a “big bang” migration. Lastly, establish a communication plan to keep stakeholders informed and engaged throughout the project.


Plan the migration of data, ensuring data integrity, security, and minimal downtime. The process will largely depend on the migration technology and methodology. This phase also includes the migration or redevelopment of applications. This may involve transforming applications into a new language or adapting them to new platforms. Another important step is preparing for the integration of new systems with existing processes and systems. Use a thorough testing method to validate functionality, performance, and security.

At Astadia, we use a mainframe migration factory setup to automate these processes and reduce the project’s costs, risks, and timeframes. Astadia’s FastTrack Platform is a collection of tools, processes, and technologies to accelerate and standardize a successful mainframe migration project.  It offers a game-changing approach to modernization, giving you the shortest project duration possible (up to 90% project time reduction), very high confidence in the results, and substantial cost savings.

Learn more: The Astadia FastTrack Mainframe Modernization Methodology


Develop a go-live strategy that includes final migration, backup procedures, and a rollback plan in case of issues. Set up systems for monitoring the new environment and supporting users post-migration. Establish a process for continuous evaluation and improvement of the new system, leveraging feedback from users and performance data.

GETTING ALIGNMENT: Whether you’re working directly with Astadia or with one of our mainframe modernization partners, we understand how to address the concerns of various stakeholders across your organization. We have modernized some of the largest, most complex systems in the world. We can tailor our approach to address your organization’s unique priorities, budget, and risk-tolerance.

HYPERSCALER SUPPORT: Astadia has completed successful mainframe-to-cloud migrations with leading cloud hyperscalers like AWS and Microsoft Azure.  We’ve been recognized by AWS for our mainframe modernization expertise, and as a Microsoft Gold Partner.  If you’re moving to Google Cloud Platform, Oracle Cloud, or any other cloud or on-premise platform, Astadia can support you.

Astadia: Your Go-To Partner for Mainframe Modernization

If you’re struggling with your legacy mainframe system, Astadia understands how to accelerate your journey and get you from A to Z in record time, with confidence.

For over three decades, we have taken on some of the biggest challenges in mainframe modernization, including cloud migration, refactoring, replatforming, DevOps, and managed IT services. We have a track record of over 300 successful migrations with world-class organizations, saving time and money, minimizing risk, and driving superior business performance.

Let’s discuss your project. Contact the mainframe modernization experts at Astadia today.

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