Typical phases of a mainframe modernization project

Modernization was once viewed as a risky, high-stakes proposition. Today, the greater risk lies in doing nothing. Here are the typical phases involved in a mainframe modernization project and how to manage risks.


17 Nov 2023

Typical phases of a mainframe modernization project

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Today, the greater risk lies in doing nothing. Organizations must get beyond the challenges inherent in legacy systems to achieve lower operating costs, improve agility, and accelerate innovation.

In this article, Astadia, an Amdocs company, provides an overview of the typical phases involved in a mainframe modernization project.

Phase 1: Mainframe assessment

The first phase of a mainframe modernization project is a comprehensive mainframe assessment. This involves identifying and documenting all of the existing systems, data, applications, and dependencies associated with the mainframe system.

When it comes to understanding their own systems, many organizations have blind spots. Applications developed and changed over decades may include sections of code written years ago. In many cases documentation is poorly written or lacking altogether.

Astadia’s FastTrack Mainframe Assessment uses a combination of proprietary tools and expert analysis to provide a comprehensive picture of a mainframe system. In most cases, we’re able to discover unused code, modifications that administrators were unaware of, or Assembler code that supplements existing applications.

The assessment phase provides a detailed and accurate picture of the current state, a list of potential modernization approaches, and a recommended path forward that aligns with organizational goals.

Phase 2: Modernization strategy planning and design

The next phase involves developing a detailed strategy for mainframe modernization. This includes deciding on the best overall approach, which may involve rehosting, replatforming, rearchitecting, or replacing. Each approach has its own advantages and challenges, and the choice will depend on factors such as budget, business goals, risk tolerance, and timeframes.

This phase also involves designing the architecture of the target system, creating a map of how the existing mainframe components will translate into a modern environment, and designing a data migration plan.

Phase 3: Implementation and testing

The implementation and testing phase is where the modernization plan is executed. This includes setting up the new system environment, migrating the data, and converting or rewriting application code. In many cases, organizations will want to preserve their legacy code by refactoring or rehosting existing applications in a new environment. It’s not uncommon to replace utilities or other relatively simple applications with commercial off-the-shelf software (COTS), or to rewrite those components from scratch.

This phase also involves testing the new system to ensure that it is working correctly and that it provides the same functionality as the old system or better. The testing process should include unit testing, system testing, integration testing, and user acceptance testing.

Astadia’s  FastTrack Migration Platform includes testing and validation components that replicate real-world user activity from the existing system, execute those activities in the new system, and validate functional equivalence. By using the TestMatch and DataMatch components as part of our fully automated migration factory, organizations can execute exhaustive testing and validation on their new system before they go live. This provides extraordinarily high levels of confidence that the new system will perform exactly as expected.

Phase 4: Cutover from Mainframe to Cloud

In this phase, the new system is deployed into the live environment and populated with live data. Typically this involves planning and executing a cutover strategy, which may include a period of running the old and new systems in parallel. With Astadia’s  FastTrack Migration Platform, users can test their new system exhaustively prior to cutover, which instills high levels of confidence and eliminates the need for extended parallel operations.

This phase also involves training users on the new system, and providing support during the transition period. The transition phase ends when the old system is decommissioned and all users are comfortably using the new system.

Phase 5: Post-implementation review and continuous improvement

The final phase of a mainframe modernization project is the post-implementation review. This involves reviewing the project's success in terms of meeting the stated business goals, and identifying any areas for improvement.

This phase also involves setting up a process for continuous improvement. This may include regularly reviewing and updating the system to ensure it continues to meet business needs, or setting up a process for ongoing training and support. Many organizations use this time as an opportunity to transition to an agile DevOps approach to development and testing.

Mainframe modernization is a complex process that requires careful planning and execution. When done correctly, however, it can provide significant benefits including cost savings, increased flexibility, and improved business agility.

Are you considering a mainframe modernization project for your organization? Contact our team today to discuss your project.


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