Mainframe COBOL to Java, C# & Cloud


COBOL to Java Banking Case Studies: ING Bank's Transition

ING Bank, ranking amongst Europe's top 10 banks, utilized the SoftwareMining Translator to transition 1.5 million lines of online and batch COBOL code (CICS/DB2 and JCL) to Java.

Decommissioning the ING mainframe was challenging. With SoftwareMining's assistance, the project was successful. We've been running smoothly on Linux since Feb 2022.
- ING Product Owner

After conducting thorough technical assessments and rigorous cost and risk evaluations, the strategic decision was made to bring the project in-house. SoftwareMining Tools were leveraged to seamlessly transform the mainframe COBOL/CICS Application into Java.

Given the mission-critical nature of the application, maintaining identical functionality between the new and original systems was paramount. This led to a significant focus on testing, involving a meticulous examination of over 2 billion transactions to compare the outputs of both systems. This comprehensive testing phase extended the project timeline to 18 months, highlighting its pivotal role in ensuring the project's success.

Another crucial consideration was the continuity of the message queuing architecture. It was essential for the new Java system to facilitate a gradual transition from IBM MQ, enabling seamless communication with the mainframe system during initial testing phases while paving the way for future independence. The code generated by SoftwareMining tools played a vital role by implementing a design that allowed underlying implementation changes without any need for alterations to the translated application's code.

The online component of the application has already been re-implemented in Java and communicates with the backend through the messaging system. One of the concerns of the bank's technical team was the 'thread safety' of the newly translated Java application and the associated libraries. A significant part of the 2 billion tests was dedicated to ensuring that parallel transactions, initiated by concurrent users, did not interfere with each other.

Lastly, as with all mission-critical applications, it was imperative that the newly generated Java application could achieve the nightly batch jobs within the same time window as the original IBM system. This requirement primarily pertained to the JCL functionalities, notably SORT operations. These operations not only needed to offer a range of features and compatibility with those available on IBM mainframes (e.g., DFSORT) but also had to deliver acceptable performance. The SoftwareMining translation of JCL to Unix shell scripts, and Java implementation of SORT, satisfied all these requirements.

Benefits of Mainframe Modernization for ING Bank

Through the modernization effort, ING Bank realized significant advantages, both in terms of financial savings and operational enhancements. This strategic transition brought about the following benefits:

Reasons for Choosing SoftwareMining

Project Factors

Testing, the most significant part of the project, required the expertise of the bank's personnel who were intimately familiar with COBOL system functions, knew how to navigate it, and what results to expect. Conducting testing in-house offered the following additional advantages:

  • Security: Ensuring that no code or data ever left the bank's infrastructure
  • Enhanced control over migration project schedules, costs, and risks
  • Efficient cycles of Translation and Testing (only translate what can be tested in the next cycle, with changes to the generated code fed back to SoftwareMining - see next point)
  • Changes to the translator: Ability to submit change requests to specific parts of the generated code before the next translation cycle
  • Interoperability with the mainframe, achieved through SoftwareMining's libraries, which dynamically converted data files housing packed-decimal fields
  • MQ migration strategy enabling MQSeries communication and potential transitions to other message queuing systems
  • Using SoftwareMining libraries for CICS Support
  • Smooth integration from JCL Migration to Unix Shell scripts and the newly translated Java code
  • Long-term strategy for moving away from DB2 database

For a detailed overview of the activities undertaken throughout the project, please see Mainframe Modernization Roadmap.



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