IBM i Modernization
IBM i Modernization Without Losing What Already Works
Paragon can modernize the user experience while retaining proven IBM i business logic, rearchitect an application on IBM i, or rebuild the complete system for a platform-independent future. The right path depends on your applications, objectives, budget, and long-term technology strategy.
Modernization options
Three Paths for Modernizing an IBM i Application
Modernization does not mean the same thing for every organization. Paragon can modernize selected interactive workflows, rearchitect an application while retaining IBM i, or convert the complete application to a new platform.
Modern Web Interface with IBM i Business Logic
Replace selected 5250 workflows with a browser interface while retaining IBM i business logic, data, and batch processing.
Application Rearchitecture on IBM i
Separate presentation and business processing, then rebuild the interactive application backend in PHP or another selected language while continuing to operate on IBM i.
Complete Application Replatforming
Rebuild the complete application and database for operation independently of IBM i on a customer-selected technology platform.
Level 1
Modern Web Interface with IBM i Business Logic
Paragon removes display-file and screen-control logic from selected interactive RPG or COBOL programs and restructures the remaining business logic for access through an API. A browser-based interface is developed using standard HTML and CSS, with an appropriate front-end framework when it provides a practical benefit.
A PHP integration layer manages communication between the web interface and the IBM i application services. The API performs the business processing and returns structured information to the web application.
This approach modernizes interactive workflows while preserving the existing IBM i business logic, database, and batch processing. Batch programs remain intact unless they are separately included in the modernization scope.
Recommended Supporting Improvements
Level 2
Application Rearchitecture on IBM i
Paragon separates the existing interactive RPG application into distinct presentation, service, and business-processing layers. We use a repeatable, AI-assisted engineering process to analyze program responsibilities and dependencies, help separate the layers, and accelerate development of the new architecture.
The browser interface is developed using standard web technologies. The interactive application backend is rewritten in PHP or another language selected with the customer, while the application continues to operate on IBM i and use DB2 for i. A web-oriented backend provides a natural foundation for APIs, JSON processing, integration, and browser communication.
Existing batch RPG can remain in place. It is changed only when batch modernization is included in the project scope. Architectural decisions, generated code, and converted functionality are reviewed, tested, and validated by experienced developers.
Recommended Supporting Improvements
Level 3
Complete Application Replatforming
Paragon rearchitects and rebuilds the complete application for operation independently of IBM i. This includes the browser interface, business logic, interactive processing, batch processing, integrations, database structures, and operational components required by the application.
The new application can be developed in PHP, Python, or another language selected according to the customer’s requirements. The database is converted and migrated to an appropriate target such as MariaDB, MySQL, PostgreSQL, or Microsoft SQL Server.
Complete replatforming requires the most extensive analysis, development, data conversion, testing, and implementation planning. It is appropriate when the customer has made a strategic decision to move the application away from IBM i and the business value supports the additional scope and risk.
Required Conversion Work
Our approach
A Disciplined Path from Existing Code to the New Architecture
Whether the project changes selected interactive programs or replaces the complete application, Paragon begins by understanding how the current system works. That includes business rules, program dependencies, database relationships, interfaces, scheduled processing, security, and operating procedures.
Modernization is divided into controlled stages with defined functionality and validation criteria. Existing behavior provides a reference for regression testing, while business users confirm that the new application supports the work they actually perform.
The objective is not simply to translate code. It is to produce an architecture that is supportable, documented, testable, and appropriate for the customer’s long-term direction.
Application Discovery
Understand program functions, data, dependencies, interfaces, batch processing, and business rules.
Target Architecture and Roadmap
Define the modernization level, target architecture, priorities, stages, responsibilities, and acceptance criteria.
Incremental Development and Validation
Build and test each stage against known application behavior and defined business requirements.
Deployment and Knowledge Transfer
Move approved functionality into production, document the new environment, and transfer the knowledge required to support it.
Every starting point
Undocumented and Older Applications Can Still Be Modernized
Many IBM i applications contain fixed-format RPG or COBOL, DDS-defined files, limited documentation, and business rules developed over decades. Paragon can analyze unfamiliar systems, reconstruct the necessary application knowledge, and define a responsible modernization path. The condition of the existing application affects how discovery begins, but it does not prevent the work.
FAQ
IBM i Modernization Questions
Do we have to replace the complete application?
No. Level 1 modernizes selected interactive workflows while retaining IBM i business logic, DB2 for i, and batch processing. Level 2 rearchitects the interactive application while continuing to operate on IBM i. Level 3 is available when the customer has decided to replace the complete platform.
What changes when a 5250 workflow becomes a web application?
Screen-control and display-file logic are removed from the selected interactive program. Business processing is made available through an API, a PHP integration layer manages communication, and a browser interface provides the user experience.
What happens to existing batch programs?
Batch programs remain intact in Level 1. They can remain on IBM i in Level 2 unless batch modernization is included. In Level 3, required batch processing is rebuilt for the selected target platform.
Can you modernize an application with little documentation?
Yes. We analyze source code, database relationships, program calls, job flows, interfaces, and business processes to reconstruct the context needed before changing or converting the application.
How does Paragon use AI during modernization?
Paragon uses repeatable AI-assisted engineering processes to help analyze existing code, identify application layers, accelerate development, and support conversion. Experienced developers review architectural decisions, generated code, and application behavior throughout the project.
Is DDS-to-DDL conversion required?
It is recommended when the application remains on IBM i because it modernizes the DB2 for i data definition while preserving the platform. For complete replatforming, the database structures and data must be converted and migrated to the selected target database.
How long does modernization take?
Timing depends on the selected modernization level, application size, code condition, dependencies, testing requirements, target technology, data volume, and availability of business users. Paragon develops a staged plan after understanding the application and desired destination.
Choose the Right Modernization Path
Tell us about your current application and long-term objectives. We’ll help determine whether interface modernization, application rearchitecture, or complete replatforming is the right approach.
Discuss your modernization project Call 800-966-6725