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 staff and our associates retain a deep understanding of a myriad mainframe technologies. Our experts are located across the globe from the Americas to Europe and Asia Pacific and 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 builds each customer a unique “conversion factory” that quickly and accurately converts complete systems on demand.

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 Works 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++
Unisys - WFL/ECL (Job Control) to 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 Works Conversion Toolset also incorporates MSS sophisticated test software:

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

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.


MSS is a software centric systems conversion company, not just a code migration company. Many companies convert COBOL to Java for a result described as “JOBOL”; the appearance of Java code with the structure and inherent limitations of the original COBOL code. The MSS systems conversion approach addresses the common limitations. For example, a specialized MSS Group class represents COBOL data items in reusable Java classes with the result that external interfaces, message queues calls to other programs and flat files can be read and written without change. MSS Groups can also be used to create microservices automatically, without coding. Please ask us for a video demonstration.

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

All MSS modernization services follow a comprehensive implementation checklist and a proven multi-stage process that embody four decades of MSS experience. Projects begin with detailed definitions of the “as-is” and “to-be” architectures together with precise definitions of roles and responsibilities. Nothing is left to chance. For example; single threaded applications written for high performance mainframe processors often perform poorly on today’s multi-processor servers. Performance, user acceptance testing and other critical success factors are rigorously defined and tracked through each project phase from inception to decommissioning the “as-is” system and ongoing support. Please ask us for the free white paper describing the implementation checklist and multi stage project implementation process.

A conversion project is the ideal time to consider cloud benefits; on-premise, private, public and hybrid. Public cloud solutions offer the ability to scale capacity on demand and the financial benefit of converting from up-front capital expense to pay-as-you-go operational expense. MSS addresses data migration, availability and performance considerations based on customer preference within the project design. We also partner with industry leading global providers to ensure any cloud implementation is both secure and manageable. Please ask us to help make the best cloud decisions for your organization as we enable the future.

MSS can run the gamut of test scripts and recorded transactions but real-time comparative testing is more effective in catching unpredicted errors and omissions. MSS proprietary test tools provide the ability to transparently parallel process live transactions, automatically comparing results between the live legacy and converted system under test. The test tool accounts for the differences in database technologies and schemas in real time. Any result differences trigger immediate alerts for corrective action. Please ask us for a video demonstration.