- Migration Pattern
- RPG/CL to Java migration
migration-pattern
Migration Pattern
IBM i (AS/400) Modernization
Legacy systems running on IBM i (AS/400) face numerous challenges – an obsolete technology stack, a shrinking talent pool, high maintenance costs, and limited business agility. Failures or delays in modernization can lead to system outages, compliance risks, and loss of competitive advantage.
SoftRoad has helped many customers migrate their legacy systems on IBM i (AS/400) to open platforms, either on-premises or or in the cloud. Using our proprietary AI-assisted conversion technology, supported by structured analysis, validation, and engineering review, we migrate both legacy code and data to true open systems and relational databases (RDBs) that fully comply with industry standards. The resulting systems are rigoriously tested, highly maintainable, and are generative AI-ready for future maintenance and enhancement.
Success Stories
With our unparalleled AI-assisted modernization technology, supported by structured analysis, validation, and engineering review, we help our clients with their IBM i (AS/400) modernization initiatives, converting RPG to Java and legacy data to relational database (RDB), delivering a true open system with high quality and low costs, which sets us apart from the competition.
A number of our clients presented their migration projects as case studies jointly with SoftRoad at major IT events in Japan. Cover pages shown below are from slides for those speaking sessions.
Case studies reference specific modernization projects delivered across different timeframes and regions. Brand names are used for illustrative purposes only and do not imply endorsement or ongoing commercial relationships.
AppModernizer for BB sales management system
at JUAS Square
AS400 Modernization
RPG/CL to Java
DB2 to SQL Server
The IT department takes an aggressive stance to avoid business risks! Breaking away from legacy systems through AppModernizer
at BSIA Symposium
AS400 Modernization
RPG/CL to Java
DB2 to PostgreSQL
Performance Improvement
Launching a distribution system that cannot be offline for even short periods in a highly challenging project environment
at Gartner IT Symposium/Xpo
AS400 Modernization
RPG/CL to Java
DB2 to Oracle
Challenges of Holding on to IBM i (AS/400) and RPG
RPG on AS/400 will eventually be replaced by modern technologies. Clinging to an outdated legacy is frustrating and inefficient. Let’s migrate and enjoy the benefits of new technology sooner.
Common Problems in Migrating from RPG to Java
Most migration companies use straight conversion
RPG coding is simply replaced with custom Java functions, inheriting the elements of the RPG system as-is.
As a result, managing the new Java system requires a deep understanding of both RPG and Java technologies.
Since it is not standard Java, generative AI tools cannot create or modify source code correctly.
With straight conversion, the existing processing method remains unchanged, leading to frequent performance issues.
Comparison testing is conducted with customer-provided test data only, effectively leaving quality assurance to the customer.
Features of AppModernizer’s Automated Conversion
AppModernizer converts RPG system to standard Java system and also provides the following advantages in the new system.
☛ Standard Java code comparable to those built by human programmers.
☛ Convert to customized Java framework.
☛ Automatically generate SQL statements and data processing procedures with high performance.
☛ Improvements such as expanding the number of digits for item IDs, etc.
Testing Tools Covering All Migration Technical Points
Instead of relying solely on customer-provided test data for quality assurance, we conduct test that covers all technical points and critical business processes to rigorously ensure quality and reduce test cost.
Comparison Test through Reproducing Actual Processing
Reliable quality is achieved only through testing with a large volume of data from many business days. We complete our tests only when data from 3 consecutive business days has been processed without any bugs.
Conducting comprehensive testing of the new Java system against the legacy RPG system presents significant complexity due to differences in architecture, data structures, and processing logic.
With AppModernizer’s automated testing, clients can have peace of mind without having to worry about complex system tests themselves, allowing clients to focus on their core objectives.
Examples of Migrated Source Code
UI Migration
Features of migrated GUI
・Improved operability with mouse and buttons.
・Customizable according to customer UI standards.
・Response speed similar to that of web systems.
AS400 Migration Performance Issues
In RPG systems, database data can be accessed directly.
In Java systems, access is through a database interface, which can lead to performance issues if the volume of database queries is high.
Straight conversion alone struggles to solve this problem. Instead, using AI to understand the functionality enables the generation of correct Java code.
Production Data Migration
If there are errors in data migration, business operation issues may arise.
Key implementation items
Over- or under-inclusion
All the data and operation patterns are rigorously checked by SoftRoad’s proprietary tool.
Data migration accuracy
We use the data migration tool to transform data across all test cases and validate the results through comparison.
Especially with the comprehensive testing, which spans a large volume of data, we ensure the accuracy of structural changes, format conversions, etc.
Key tasks in data migration
Data migration was performed successfully across a wide range of enterprise migration projects we have completed.
Implement Specification Changes During Migration
Prolonged system freezes during migration can be avoided using our catch-up solution.
AppModernizer can perform automated conversion. If customer provides the latest RPG source code after each update, we can integrate the changes by quickly converting them into Java code.
Migration cases
Wholesale core system
- Development process
- Inventory & slimming, migration design, UI design – system test, user acceptance test support
- Migration information
- RPG to Java
CLP to Java/Shell
DB2 for i to Enterprise Postgres SE 14
IBM i V7R4 to Red Hat Enterprise Linux 8.4 - Current system scale
- RPG：443KL
CLP：91.6KL - Added new functions scale
- Java：110KL
- Development period
- 21 months
Order, sales, and inventory management core system
- Development process
- Inventory & slimming, migration design – migration test
- Migration information
- COBOL, RPG, RPGLE to Java
CLP, CLLE to Java/Shell
C to Java/C
DB2 for i to SQL Server 2019
IBM i V7R3 to Red Hat Enterprise Linux 8.4 - Current system scale
- RPG, RPGLE：685.3KL
CLP, CLLE：269.0KL
COBOL：2,834.8KL
C：4.8KL - Development period
- 22 months
Logistics management system
- Development process
- Inventory & slimming, migration design – migration test, system test & user acceptance test support
- Migration information
- RPG, RPGLE to Java
CLP, CLLE to Java/Shell
DB2 for i to SQL Server 2019
IBM i V7R2 to WindowsServer2022 Standard Edition - Current system scale
- RPG：614.1KL
CLP：6.3KL - Development period
- 15 months
Inter-company information sharing system
- Development process
- Inventory & slimming, migration design – migration test, system test & user acceptance test support
- Migration information
- RPG to Java
CLP to Java/Shell
DB2 for i to SQL Server 2019
IBM i V7R3 to WindowsServer2022 Standard Edition - Current system scale
- RPG：1,943KL
CLP：30.2KL - Development period
- 18 months
Sales management system
- Development process
- Inventory, migration design, specification documentation, source code migration – system test, user acceptance test support, Go-Live
- Migration information
- RPG to Java
CLP to Java & PowerShell
DB2 to Oracle19c
IBM i V7R1 to WindowsServer2016 - Current system scale
- RPG：110KL
- Development period
- 11 months
CONTACT
For more details about system migration,
feel free to reach out to us.