TransUnion HPE NonStop COBOL-to-Java Modernization Case Study

TransUnion used SoftwareMining's automated, rule-based COBOL-to-Java converter as part of the migration of more than 200 credit-processing applications running on HPE NonStop, formerly Tandem. The portfolio included approximately equal numbers of online and batch COBOL applications, which were converted into maintainable Java for deployment on a modern enterprise platform.

The migration enabled TransUnion to retire the legacy application platform while preserving the established processing behaviour of its business-critical credit applications.

Project at a Glance

Customer	TransUnion
Industry	Credit Reference Services
Source Platform	Tandem (HPE NonStop) COBOL
Application Portfolio	More than 200 applications, approximately 50% online and 50% batch
Target Technology	Java
Reported Outcome	No production outages attributed to the new system and no post-go-live defects reported

Migration Decision

As the Tandem environment approached end of life, TransUnion selected migration to Java instead of porting and upgrading the existing COBOL applications. This provided a path away from the legacy environment while preserving the established credit-processing behaviour.

Conversion Approach and Timeline

Automated conversion of COBOL modules to Java, with targeted refactoring to improve readability and supportability.
Most compilation and build issues were identified and resolved during the first two months of conversion.
Online and batch processing flows were validated against the behaviour and outputs of the existing applications.

There were far less compilation errors than we planned for and the initial two months of COBOL to Java conversion shook out many issues. Very few occurred after that phase.

TransUnion Technical Lead

Production Results

More than 200 online and batch COBOL applications migrated to Java.
No production outages attributed to the new Java system after go-live.
No post-go-live defects reported in the converted components.
The original Tandem application environment was retired.

We could not have completed this project without it. We have had zero production system outages caused by the new system and there have been no defects found. This was a huge effort and successful because of SoftwareMining.

TransUnion Project Manager