Legacy PL/1 Migration

Our Automated PL/1 Migration solution delivers modern Cloud-enabled applications and databases that are functionally equivalent to their legacy counterparts, eliminating the hassle and expense of PL/1 and the mainframe. This reduces cost, allows for deeper integration, and enables customisation to meet business requirements.

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Discussing the 2022 Mainframe Modernisation Report

60 minutes

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Why modernise?


Scarcity of domain expertise

Developers who understand PL/1 and mainframe technology are reaching retirement age and no one is trained to replace them, resulting in a steadily diminishing talent pool. As this shortage grows, the costs and risk of relying on PL/1 will continue to rise.

Limited flexibility

Companies are rapidly moving to modern environments and practices such as DevOps and the Cloud. PL/1 and the underlying systems that support it were not designed for modern IT, resulting in difficult integrations and limited flexibility.


Exorbitant costs

Mainframes running PL/1 cost as much as 4,500 per cent more to operate than equivalent Cloud counterparts. This figure is compounded by the rising licensing and maintenance fees for ancillary mainframe applications and databases. 

Automated PL/1 Refactoring


Our Automated Refactoring solution provides a turnkey modernisation of your PL/1 codebase to object-oriented Java or C#, and your associated mainframe databases to relational models deployed to the Cloud or on premises. This preserves the benefits of legacy systems while empowering organisations to leverage the advantages of newer platforms. It unlocks a whole new world of quality and scalability from automated testing to quality assurance, and the ability to leverage containerised deployments and orchestration with Docker and Kubernetes.

  • Refactored applications must remain functionally equivalent to their original counterparts
  • Refactored applications must be easily maintainable, attain SonarQube A ratings, and follow object-oriented concepts and paradigms
  • Refactored applications should perform as well as, or better than, the original applications
  • Refactored applications should be Cloud-ready and delivered using a standard DevOps toolchain and best practices

Our Automated PL/1 Refactoring solution delivers modern Cloud-enabled applications that are functionally equivalent, and can be extended and maintained using any modern IDE. The solution supports all aspects of mainframe-based PL/1 applications, including databases (e.g., Db2, IDMS, IMS, and VSAM), TP monitors (e.g., CICS, IMS TM), JCL and supporting utilities (e.g., IDCAMS, SORT, etc.).

Automated PL/1 Refactoring revolves around an iterative incremental methodology. An initial refactoring pass of the PL/1 code is performed to determine the level of program remediation necessary to perfect results. The solution also allows for customisation of rules in all phases of the refactoring process according to specific customer requests for target architecture and code syntax. Individual customer requirements are incorporated back into the tooling after each pass, and the result is functional equivalence with maximum readability and performance.

PL/1 refactoring presents unique challenges including the handling of pre-processor statements like %DECLARE, %INCLUDE, %IF - %THEN - %ELSE, %DO - %END, etc. Pre-processor's separate program and include file construct has to be preserved, otherwise overall maintainability of the target application will suffer. When PL/1 source contains pre-processor statements, the source code is different from the code passed to the PL/1 compiler. The pre-processor statements are executed just before the compile and may alter the source code by adding or removing code parts. Our Automated PL/1 Refactoring solution uses a combination of sources before and after pre-processing, which allows complete coverage of PL/1 functionality, improving the maintainability of the refactored code.

Once the PL/1 applications and databases are refactored, Java and C# developers can extend application functionality for Cloud optimisation using standard DevOps tools and CI/CD concepts that simply aren’t available for mainframe applications. Precious business logic from the legacy system is preserved, while levels of optimisation can be applied to deliver efficiencies and business benefits such as elasticity, granular service definition, and easy integration with Cloud-native services.

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Over 35 years of PL/1 and mainframe modernisation experience

More than 500 successful modernisation projects completed

Over 2.5 billion lines of code refactored through automation

Intelligent modernisation, unparalleled experience


Additional resources to help you modernise



It's not fun living with PL/I

This whitepaper details the business case, challenges, and solutions for moving legacy PL/I applications to modern platforms.

Read whitepaper





Fiserv: Modernising the Galaxy platform

Learn how Fiserv reduced the risk of failure, eliminated vendor lock-in and lowered operating costs through modernising their custom platform.

Read case study





2022 Mainframe Modernisation Report

Exploring the impact of the new era of digitalisation and change on the current state of legacy systems and organisations' modernisation plans.

Read report



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02 Dec 2022 by Tim Jones, Managing Director of Application Modernisation, Advanced

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21st Oct 2022 by Tim Jones, Managing Director of Application Modernisation, Advanced

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10 Jun 2022 by Rob Anderson, Vice President of Marketing and Product, Advanced

News & Opinions

BLOG // 06-06-2023

Industry Insights: Mainframe Migration and Cloud Adoption in Healthcare

by Tim Jones, Managing Director - Application Modernisation

Industry Insights: Mainframe Migration and Cloud Adoption in Healthcare

The Future of OpenVMS: Risks and Opportunities

The OpenVMS operating system has been the driving force behind numerous mission-critical business applications worldwide for decades. Although OpenVMS…

by Tim Jones, Managing Director - Application Modernisation

BLOG // 15-05-2023
The Future of OpenVMS: Risks and Opportunities