With over 2,000 branches nationwide, a leading Indian bank sought to modernize its legacy COBOL-based applications to align with its growing business needs and Windows-based infrastructure. Recognizing the risks of operating mission-critical systems on aging technology, the bank partnered with Bangalore Softsell Ltd to execute a robust migration using LeMiT — Softsell’s proprietary legacy modernization platform.
The objective: Migrate and optimize legacy COBOL systems into a scalable, multi-tiered Visual Basic 6.0 environment, while improving performance, maintainability, and user experience.
The bank’s existing COBOL applications, developed over decades, were deeply embedded in day-to-day operations. While functionally stable, they were:
Monolithic and hard to maintain
Lacking in GUI capabilities
Unable to easily integrate with modern office components
Not designed for rapid response to changing business requirements
The bank needed a proven solution that could retain the core logic and migrate to an open, interoperable platform with modern user interface capabilities — all with minimal disruption and maximum reliability.
Using LeMiT and the KINETIC project management methodology, Softsell executed a full-stack migration:
Presentation, business, and database layers were rebuilt in Visual Basic 6.0
COBOL file structures were converted into a relational database (RDBMS)
Designed an n-tier architecture for maintainability, scalability, and system interoperability
Function & Variable Analysis: LeMiT analyzed all COBOL functions to retain only those essential to operations.
Achieved 71% average optimization in code functions and 27% in unused variables, reducing application bloat significantly.
Non-trivial processes were wrapped in centralized error handlers to prevent runtime crashes — covering file I/O issues, data conflicts, division errors, and more.
Nested IF-ELSE COBOL structures were replaced with more elegant VB Select Case logic to streamline decision branches and improve performance.
All message strings were converted into constants, enabling centralized messaging and reusability across modules.
All critical operations — especially financial transactions — were embedded within VB transaction blocks to ensure atomicity and data integrity.
- Modern GUI Controls: COBOL green screens were replaced with intuitive elements like dropdowns, option buttons, date pickers, and checkboxes
- Dynamic Validations: Mandatory fields were visually marked; data type restrictions enforced through VB control properties
- Display-Only Fields: Clearly marked as read-only using greyed-out visuals
- Date Processing: Handled using Windows Date Picker control, eliminating format errors
- Smart Office Integration: Users could email, print, or export data without exiting the application
By modernizing its COBOL systems using Visual Basic and LeMiT, the bank:
Future-proofed its core systems for continued scalability
Significantly reduced technical debt and code complexity
Improved UI/UX, empowering users with an intuitive interface
Integrated seamlessly with modern tools and platforms
Built a flexible foundation ready for ongoing digital transformation
COBOL, Visual Basic 6.0, RDBMS, LeMiT™, KINETIC Methodology, Windows GUI Components
LeMiT is a proprietary platform of Bangalore Softsell Ltd. This case study illustrates one of many successful migration implementations. Actual results may vary by use case and system complexity.
