Why are organisations moving off the mainframe now?
Mainframes have long been a reliable backbone for industries like finance, healthcare, and government. Yet modern enterprises face pressures to move faster, scale dynamically, and innovate continuously – needs that legacy systems increasingly struggle to meet.
Scalability and flexibility are major drivers. Cloud platforms allow workloads to scale up or down instantly, supporting fluctuating demand without overprovisioning, which is particularly valuable for industries with seasonal spikes or unpredictable usage patterns.
Cost efficiency is another motivator. Mainframe hardware and software licensing are expensive, whereas cloud platforms offer pay-as-you-go models that free IT budgets for innovation rather than upkeep.
Agility is crucial for staying competitive. Deploying new features, testing updates, and integrating modern tools can take months on a mainframe but only weeks or days in the cloud.
Security and compliance also play a key role. Every modern cloud provider maintains continuously updated security frameworks, helping organisations manage risks without bearing the full operational burden.
Finally, analytics and AI capabilities make migration compelling. Cloud platforms enable integration with real-time analytics, machine learning, and data lakes, unlocking insights that were difficult to access with siloed mainframe data.
Aging hardware and workforce challenges further increase urgency. With mainframe specialists retiring and spare parts harder to source, migration ensures business continuity while reducing dependence on obsolete systems.
Together, these factors make migration not just an IT upgrade but a strategic move to future-proof the business.
90% reduction in deployment time and 2x increase in operating speed through a large-scale migration to the cloud
What does migrating from a mainframe to the cloud involve?
Migrating from a mainframe means moving applications, data, and workloads to modern cloud platforms. The approach varies based on business priorities, risk tolerance, and timelines, and most organisations combine multiple strategies to minimise disruption while unlocking cloud benefits.
What are the main strategies for migrating a mainframe?
Migration strategies are guided by business objectives, technical complexity, and acceptable risk levels. Let’s look at them in more detail:
Rehosting (lift and shift)
Moves applications with minimal code changes, reducing infrastructure costs quickly but not fully exploiting cloud capabilities.
Replatforming
Modest adjustments allow applications to integrate better with cloud services while balancing speed and mainframe modernisation.
Refactoring or rearchitecting
Full redesigns maximise cloud benefits, including scalability, AI integration, and advanced analytics, though they require more investment.
Replacing with modern solutions
Retiring legacy systems in favour of commercial software or cloud-native services accelerates modernisation but may require process changes.
Strategic assessments of cost, compliance, time-to-market, and workload criticality guide the choice of strategy. Most organisations adopt a mix to balance immediate efficiency with long-term innovation.
Best fit varies: rehosting suits quick savings with minimal disruption, replatforming supports faster adoption with moderate change, refactoring enables long-term innovation, and replacing is best for organisations ready to embrace modern platforms.
Read more related articles on our blog:
How to approach mainframe migration and plan your actions?
Thorough assessments form the backbone of a successful migration roadmap. Key focus areas include:
- Application complexity: Evaluating all mainframe applications to determine migration difficulty.
- Data flows: Mapping how data moves across systems and identifying critical integration points.
- Dependencies: Understanding interconnections between applications, databases, and services to prevent disruptions.
- Technical debt: Identifying outdated code or unsupported components that may hinder migration.
These insights allow organisations to prioritise workloads, mitigate risks, and identify opportunities for main modernisation, ensuring the migration delivers tangible business value.
What product options are available to simplify mainframe migration?
The complexity of mainframe systems means most organisations turn to specialised cloud migration tools and platforms to smooth the path to a cloud environment.
As an AWS Partner, at Future Processing we may leverage AWS Transform – the first AI agent-based service enabling migration and modernisation of .NET, mainframe, and VMware workloads.
Agents automate complex tasks and perform them simultaneously, which enhances overall performance and speeds up modernisation processes of hundreds of apps at the same time while maintaining high quality and control.
AWS Transform supports cross-organisational and cross-functional team collaboration, and it reduces both modernisation and maintenance costs. AWS reports that this innovative tool is able to accelerate the transformation of IBM z/OS applications from years to even months.
Another example is OpenFrame from TmaxSoft, which enables enterprises to rehost mainframe workloads – such as COBOL applications, CICS transactions, IMS databases, and VSAM files – onto Linux servers or cloud environments with minimal code changes. This approach preserves existing functionality while helping companies cut down on expensive mainframe licensing and maintenance costs.
OpenFrame also provides runtime compatibility layers and migration utilities, so legacy applications behave as they did on the mainframe but run in a more flexible, cost-efficient environment. By doing so, businesses can modernise in phases: moving workloads quickly while laying the groundwork for further refactoring or integration with cloud-native services down the line.
Beyond OpenFrame, other vendors offer rehosting, emulation, and automated code-conversion tools designed to address different aspects of migration. These products give organisations options to align their migration journey with their risk appetite, timelines, and long-term modernisation goals.
What key challenges should businesses anticipate during migration?
Mainframe migration is rarely straightforward, and organisations must be prepared to navigate a range of challenges that can complicate even the most well-planned projects. Here is a list of some of them, which you may want to consider:
Complexity in legacy systems
Mainframes often host decades of accumulated applications, integrations, and customisations. Understanding these interdependencies is critical, as even small missteps can disrupt essential business processes and lead to costly operational downtime.
Undocumented business logic
Many legacy applications rely on tacit knowledge embedded in code rather than formal documentation. This makes it difficult to fully grasp how workflows operate and what needs to be preserved during migration, risking errors that can slow operations or affect service delivery.
Data integrity issues
Moving large volumes of critical data to a new platform carries the risk of corruption, loss, or mismatched formats. Inaccurate or incomplete data can undermine decision-making, delay business processes, and damage customer trust.
Read more: Data integrity: key principles for reliable and accurate data
Skill gaps
Mainframe expertise is increasingly scarce, while cloud and modern development skills are in high demand. If knowledge transfer is not managed effectively, projects may stall and ongoing operations can suffer from insufficient support.
Regulatory compliance sensitivities
Industries such as finance, healthcare, and government face strict regulatory requirements for data handling, privacy, and auditability. Non-compliance during migration can disrupt operations, halt go-live plans, and expose the organisation to legal or financial penalties.
Recognising these challenges early allows organisations to develop mitigation strategies, such as phased migrations, robust testing, and cross-functional teams combining legacy expertise with cloud know-how. Proper planning transforms potential obstacles into manageable steps toward a successful migration.
How does mainframe migration unlock business growth?
Migration is a catalyst for digital transformation. Modernised infrastructure and applications enhance operational efficiency, automate routine processes, and reduce system downtime, accelerating time-to-market for new services.
It also fosters innovation, providing access to AI, machine learning, advanced analytics, and modern development frameworks for experimentation and rapid iteration. This enables businesses to enhance customer experiences with personalised services, real-time insights, and seamless digital interactions.
Finally, migration helps unlock value from legacy assets, converting previously siloed or underutilised data and applications into actionable insights and competitive advantages. In short, mainframe-to-cloud migration turns an aging IT backbone into a springboard for growth, agility, and long-term resilience.
Keep your business at the forefront of cloud innovation, maintaining cost efficiency, mitigating risks, and ensuring regulatory compliance.
FAQ
Is migration a one-off event or an ongoing journey?
Migration is rarely a one-time project; it’s an ongoing journey. After the initial move, organisations often enter a phase of continuous optimisation, leveraging new cloud services, serverless architectures, AI capabilities, and advanced analytics. This iterative approach ensures systems remain scalable, resilient, and aligned with evolving business needs.
What are IR challenges in migrating mission-critical workloads (e.g. in finance, insurance)?
Highly regulated industries face stringent performance, security, and continuity requirements. Any downtime or data inconsistency can have major financial or reputational consequences. Successful migration in these contexts usually involves a staged, carefully governed approach, including extensive testing, redundancy planning, and audit-ready processes to maintain compliance while minimising risk.
How does migration ease resource challenges like COBOL developer shortages?
Legacy mainframes often rely on specialised skill sets that are increasingly rare. By modernising code into mainstream languages such as Java or C#, organisations can access a broader talent pool, simplifying development, maintenance, and support. This not only reduces dependency on scarce mainframe experts but also accelerates innovation and adoption of modern development practices.
What’s the return on investment from migration?
ROI extends beyond immediate cost savings. Organisations benefit from lower CapEx, reduced maintenance and licensing costs, and improved operational agility. Migration also provides long-term flexibility, allowing businesses to adapt to changing market demands, integrate modern technologies, and scale efficiently. Hybrid strategies – blending selective modernisation with cloud migration – often deliver the best balance of cost efficiency and innovation potential, turning migration into a growth enabler rather than just an infrastructure shift.
