IBM and Unisys mainframe modernization experts MSS International offer a unique approach to the elimination of dependencies on the skills required to maintain legacy applications and costly proprietary mainframe software environments.

System Conversions

MSS builds each customer a unique “conversion factory” that quickly and accurately converts complete systems on demand.

MSS takes an iterative approach, building a dynamic systems conversion factory that is specific to each customer’s need, placing a strong emphasis on performance. MSS approach is unlike many competitor’s “blackbox” conversions that are static, one-time code migrations which often perform poorly on today’s multi-processor servers.

When complete, the factory enables immediate migration of new or modified code on demand, accurately producing output that is test ready. Typical code freeze requirements during the conversion project are eliminated. Each custom factory is retained by MSS to be quickly redeployed for additional projects.

Cloud benefits are driving enterprises to re-engineer or replace their existing mainframe applications; often a risky and expensive strategy. MSS offers a safe, low cost alternative by migrating the existing mainframe applications to the cloud.

Whether on-premise, commercial or hybrid, cloud security and systems management considerations are paramount. MSS will collaborate with the customer’s preferred in-house or third-party specialists to ensure all regulatory and other requirements are met. MSS also collaborates with some of the leading global specialists and can engage them when appropriate. MSS conversions make use of modern technologies and concepts such as RESTful services, SpringFramework, Angular, KAFKA, and others.

MSS staff and our associates retain a deep understanding of a myriad mainframe technologies. Our experts located across the globe have been handpicked for their deep domain knowledge and proven expertise.

Please contact MSS to discuss your needs and we’ll match the appropriate and highly skilled individual with your needs, no matter how big or small.


MSS approaches each of our projects with tried and tested methodologies customized to the unique customer project dynamics and requirements.

The “as-is” discovery is completed by MSS and may include a specialist third party to document a comprehensive assessment report serves as the project baseline. The “to-be” state is defined in collaboration with the customer and their preferred suppliers.

A design document is created together with a conversion factory build plan that considers the client’s specific needs. Stakeholder roles, responsibilities, interdependencies, project tasks and the governance plan are clearly defined and documented from the initial assessment through ongoing maintenance and support.

The process sets clear expectations and minimizes communication errors from the start to ensure smooth progress while reducing the potential for surprises and rework.

The MSS conversion factory is developed using tools and components from the MSS Works Software Suite. The factory is optimized and validated iteratively until a 100% automated conversion is complete. Code created by the completed factory is test ready.

Many customers take the opportunity to make additional changes, for example by replacing middleware or adding integrations that were previously difficult to achieve. As a result, testing may be different for each project but, in most cases, the final test utilizes an MSS Test Platform that enables the converted system to transparently shadow the production system, automatically comparing results across the different data stores and flagging any exceptions.

The MSS plan includes any necessary user and operations training, “go-live” steps and a period called “hyper care”. The successful go-live is not the end of the story. Plans typically include a warranty support period with ongoing production support, decommissioning the systems that have been replaced, future modernization recommendations and, of course, a comprehensive project review.


MSS key differentiator is our advanced software tools and middleware. These instantiate the expert knowledge and project experience gained over four decades.

The MSS Conversion Toolset incorporates the discrete language and data migration software components available for use in a custom built “conversion factory”. The list below is indicative of our current capabilities. Please contact us for more information:

MSS Language Migration Platform
IBM, Unisys, Microfocus - COBOL to Java
Unisys - LINC/EAE to Java
Unisys - Algol to C++
IBM Online - CICS to Angular, KAFKA, emulation as required
IBM Batch & JCL - SpringBatch or standalone
Unisys - WFL/ECL (Job Control) to SpringBatch or Bash or Perl script
XGEN to Java

MSS Data Migration Platform
Database migration and maintenance administration (Persistence Workbench)
Unisys - DMS/DMSII to Oracle/DB2/SQL Server
VSAM/C-ISAM to Oracle/DB2/SQL Server

MSS Testing Platform
Multiple data source comparison (e.g. Compare VSAM with DB2)
Transaction/data based co-existence/synchronization

The MSS testing methodology can also incorporate accelerative robotic testing automation:

MSS Testing automation provides testing software for non-technical users. It records a test case while you are doing it and draws it step by step. Tests are stored in a library and can be played back at any time. Tests are editable and can draw on utilities for provision of specialised test data and can simulate multiple-user playback. Tests can be recorded and played on mainframes and tuned to perform the same test on alternate platforms.

The MSS Works Runtime Suite includes the runtime software required to operate the customer’s converted system together with the essential links between the converted applications and the customer’s target operating environment. The list below is indicative of our current capabilities. Please contact us for more information:

MSS Runtime Core runtime support library COBOL Groups emulation library Database support library Flat file support library Microservice enabler CICS support library

MSS Infrastructure Communications infrastructure (telnet, http, MQ, CCF) TP monitor Job Scheduler Web based terminal emulation Database caching server

Additional capabilities are in development, please contact us for more information.

MSS is committed to providing a conversion path that precisely fits the customer’s preferred target platform.

Each customer’s MSS Conversion Factory is tuned, based on their unique requirements, to support available features while making the best use of their existing and future state requirements. MSS supports containerized deployments to JEE, Spring Boot, Spring Batch (JSR-352) and Docker. We also support in-house deployments to Linux, Windows and z/OS.


The MSS position on AI and its efficacy in conversion of programming languages is that it goes some way but not the whole way. For a technically successful overall transformation of an application, currently all AI solutions must be combined in some way with human experience and pre-existing robust technologies that interlink together to provide a trusted holistic outcome.

Yes, we’ll even convert a representative sample of your own code at no cost. Please contact us for details.

MSS Natural Java - For migrated code that looks like it was written by a human, MSS combines AI and our own robust internal frameworks to enhance migration outcomes. The MSS Application Performance Optimizer (MSS APO) drives increased performance and accelerates application migrations to the cloud. It reduces latency, network activity, infrastructure requirements and offers dramatic reductions in IO operations. The MSS Synchronizer allows progressive and flexible deployment of the new application while continuing to run the business with the old application. (Both will run side by side in production with bi-directional data and functional synchronization until the new one is proven ready to take over completely).

MSS is a specialist vendor in the mainframe modernization space and has a multitude of relationships and experience working with system integrators. Our system integrator partners provide the critical governance and testing outsourcing services needed for our larger clients and projects.

The short answer is yes you can, however - given the nature of the non disclosure arrangements for most of our engagements, unfortunately MSS and most MSS clients themselves are unable to communicate to external 3rd parties. MSS will always do our best to accommodate reference calls where possible. MSS has completed over 60 projects globally with Fortune 500 companies as well as government agencies. Please contact us to discuss.