Taking a Comprehensive, Strategy-Driven Approach to Mainframe Modernization with Amazon Web Services

Enterprises operating on mainframes today face urgent pressures to modernize. Talent shortages, rising operational and licensing costs, and the limitations of monolithic legacy systems all constrain innovation, agility, and competitiveness. At the same time, organizations must navigate a broad array of modernization patterns, tools, and architectural decisions.

AWS addresses these complexities with a disposition strategy—a structured, multi-pattern approach designed to modernize large, tightly coupled mainframe applications. This strategy helps organizations break down legacy estates into manageable components, define target states, sequence migrations, and integrate remaining workloads. As an AWS partner, Softprom supports customers throughout this end-to-end transformation journey.

Rather than treating modernization as a set of isolated projects, the disposition strategy establishes a unified, holistic roadmap that accelerates migration, minimizes risk, and aligns technical execution with business outcomes.

Define a North Star: Building Alignment Across the Enterprise

Mainframe estates differ widely across industries and geographies. With multiple stakeholders—business leaders, application owners, and technical teams—many organizations lack a cohesive vision for the future of their mainframe systems.

AWS modernisation success begins with defining a North Star, a shared vision endorsed by the C-Suite and often the Board of Directors. This vision should answer three essential questions:

• Why are we modernizing?
• Where are we going?
• When will it happen?

Without a unifying direction, modernization efforts often become fragmented, with different teams applying different strategies, sometimes even increasing mainframe usage instead of reducing it. A clear North Star aligns teams, accelerates delivery, and keeps modernization efforts focused on measurable outcomes.

Business Criteria: Balancing Functionality, Agility, and Innovation

Business needs for modernization typically fall under two categories:

Category 1: Maintain Business Functionality—Modernize Technology

In many cases, organizations do not want to change the functional behavior of mainframe applications. These systems may contain highly optimized business logic built over decades, and users may rely on existing processes—even green-screen interfaces—for high-efficiency workflows.

For these workloads, AWS offers options such as:

• Refactor with AWS Transform for mainframe to move from COBOL to Java and relational databases
• Re-platform with AWS Mainframe Modernization to migrate to mainframe-compatible runtimes in the cloud

The value comes from improved resilience, scalability, and agility—without functional disruption.

Category 2: Enhance Functionality—Break Monoliths and Enable Innovation

Other applications require functional enhancements, improved customer experience, real-time capabilities, or decomposition into microservices. These workloads benefit most from the reimagine pattern, which involves rewriting and rearchitecting applications using modern AWS-native services.

Business drivers in this category include:

• Faster time-to-market
• New revenue streams
• Real-time customer experiences
• Expansion into new markets
• Integration with modern technologies (AI, event-driven systems, APIs)

These applications should be prioritized when modernization outcomes directly improve business competitiveness.

Technical Criteria: Evaluating Feasibility, Complexity, and Risk

A well-designed disposition strategy considers both organizational and application-level technical factors.

Organizational Considerations

• Data center exit deadlines → Rehost or re-platform for speed and risk mitigation
• Vendor contract renewals → Refactor or reimagine to avoid costly licensing
• Mainframe talent availability → Move toward Java-based or cloud-native stacks

Application-Level Technical Assessment

A thorough evaluation should include:

• Source technologies (COBOL, PL/1, Natural/Adabas, IDMS, etc.)
• Data structures and volumes (IMS DB, Db2, VSAM)
• Degree of coupling between workloads
• Integration complexity
• External interfaces and dependencies

This assessment ensures the right modernization pattern is selected for each workload—minimizing risk and avoiding unnecessary reengineering.

Strategy Development: Building a Business-Outcome-Driven Program

Successful modernization programs:

• Work backwards from the organization’s North Star
• Align modernization with business priorities
• Plan the entire portfolio from the beginning
• Balance quick wins with long-term strategic goals
• Define clear metrics for technical and business success

Without top-down alignment, modernization can stall or become fragmented.

Avoid the “Rebuild Everything” Trap

AWS experience shows that:

• ~80% of mainframe applications do not require functional changes
• ~20% require full reimagination

Customers such as Goldman Sachs and Transamerica achieved large-scale mainframe exits by combining:

• Refactoring at scale with AWS Transform
• Re-platforming to COBOL-compatible runtime environments
• Selective reimagination of workloads that require modernization

This multi-pattern approach accelerates modernization while preserving valuable business logic and reducing operational costs.

Conclusion: The Time to Modernize Is Now

Mainframe modernization is becoming increasingly urgent. Beyond cost, talent, and operational pressures, the rise of generative AI is widening the productivity gap between modern codebases and legacy mainframe environments. Organizations relying on COBOL, Assembler, or PL/1 will face growing competitive disadvantages as peers adopt cloud-native development and AI-assisted engineering.

The AWS disposition strategy—combined with Softprom’s regional expertise and implementation support—provides a structured framework for modernizing mainframe landscapes with confidence. By adopting a multi-pattern, business-aligned strategy, organizations can retain decades of valuable business logic while accelerating innovation and preparing for the future of cloud-native development.