Overview of the Migration Project
Following detailed technical, cost and risk assessments, ING selected a
customer-controlled delivery model. The bank retained responsibility for
project management, testing, target architecture and deployment while using
SoftwareMining's tools to convert its COBOL, CICS, DB2 and JCL applications
into Java. Large-scale transaction testing was then used to validate
functional equivalence before the modernized application entered production
on Linux in February 2022.
Because the system was mission-critical, maintaining identical functionality was essential.
More than 2 billion transactions were processed during
side-by-side testing
to verify that both the COBOL and Java systems produced identical outputs.
This extensive validation phase extended the project to 18 months, but ensured total reliability.
Continuity of the messaging architecture was also important. The converted
Java application continued to integrate with
IBM MQ
during testing and transition. SoftwareMining's generated messaging
interfaces separated the COBOL business logic from the underlying messaging
implementation, allowing the integration layer to be configured or adapted
without changing the generated business logic.
Thread safety and concurrency were another major focus.
The Java system underwent intensive parallel transaction testing to confirm that concurrent user sessions did not interfere with one another.
The batch component also had to complete within the processing windows
established for the original IBM mainframe application. Using SoftwareMining's
JCL-to-Unix shell conversion
and Java SORT implementation, the bank maintained its required nightly batch
processing windows. See our technical discussion of
COBOL, Java and C# application performance
.
