Several organizations continue operating AS400 (now IBM i) systems for mission-critical business functions. These systems have demonstrated remarkable durability, with installations running successfully for decades. Legacy AS400 systems encounter major challenges when businesses need to connect them with modern tools and applications. 

What’s the solution for businesses seeking to modernize without abandoning their AS400 investments? RPG code refactoring. 

RPG code refactoring enables businesses to systematically improve legacy AS400 applications while preserving decades of built-in business logic. This approach recognizes the substantial investment organizations have made in AS400 infrastructure and the embedded knowledge contained within custom applications. Rather than replacing existing systems, a costly and risky proposition, refactoring the AS400 application codebase allows enterprises to modernize operations and drive growth. 

AS400 RPG Refactoring – Understanding the When and How  

Businesses facing increasing integration challenges with modern systems should consider RPG refactoring as a strategic option. The decision to refactor the AS400 RPG codebase often comes at critical inflection points in an organization’s technology roadmap, particularly when legacy applications still deliver core business value but struggle with connectivity to newer platforms. 

Several parameters indicate the right time for AS400 RPG code refactoring: 

• Rising Maintenance Costs – When maintenance expenses begin climbing due to legacy code complexity, refactoring offers a path to simplified maintenance and reduced operational overhead. 

• Functional Extension Requirements – Businesses need to extend existing applications with new functionalities but find themselves constrained by outdated code structures that resist modification. 

• Performance Bottlenecks – Performance issues emerge as transaction volumes grow beyond what the original code design anticipated, impacting user experience and business operations. 

Businesses looking to adopt a strategic RPG code refactoring approach should partner with an experienced IBM AS400 consulting company. This collaboration enables businesses to hire specialists, who possess deep knowledge of both legacy RPG formats and modern programming techniques—a rare combination in today’s IT landscape. Their expertise allows them to identify which code segments warrant refactoring and which should remain unchanged, creating a balanced approach that minimizes risk. 

Dedicated iSeries managed services providers bring structured methodologies developed through numerous successful modernization projects. This experience results in faster refactoring timeframes and fewer disruptions to business operations. IBM iSeries services providers  can establish proper testing frameworks that ensure refactored code maintains complete functional equivalence with original applications. 

How AS400 Consultants Simplify Technological Integrations Through RPG Refactoring 

IBM iSeries services providers unlock the full potential of legacy AS400 systems through strategic RPG code refactoring that bridges traditional applications with modern technologies. Careful modernization of existing code structures enables seamless integration without requiring complete system overhauls. 

Key technological integrations implemented by consultants through AS400 RPG refactoring are: 

1. RESTful and SOAP Web Services Integration

The recent version of RPG language is RPG IV and it is compatible with the latest REST APIs and web services. IBM iSeries consulting firms implement integrated web services for IBM i that convert traditional applications into service-oriented architecture components. This approach allows legacy applications to communicate via standard HTTP requests using either RESTful principles or SOAP protocols. 

Businesses can expose their AS400 business logic to external systems while maintaining core functionality. This integration enables real-time data sharing between AS400 systems and modern applications, improving operational efficiency and customer service response times. 

2. Electronic Data Interchange (EDI) Integration

Electronic data interchange integration with IBM i systems becomes easier through refactoring. An IBM AS400 consulting company can refactor RPG code and integrate EDI tools to support automated information flow between applications, eliminating manual data entry processes. 

This integration reduces human errors while accelerating transaction speeds from order placement to billing cycles. iSeries managed services providers ensure that refactored applications comply with trading partner protocols throughout implementation, maintaining business relationships and regulatory compliance. 

3. Cloud Analytics Integration

Refactored AS400 applications can work effectively with cloud ecosystems. Professional consultants restructure monolithic programs into modular RPGLE that connect with cloud analytics platforms. 

This conversion preserves trusted IBM i applications while unlocking cloud advantages such as scalability and flexibility. Businesses gain access to advanced analytics capabilities without abandoning their proven AS400 business logic. 

4. Workflow Automation Integration

Strategic code refactoring enables workflow automation that streamlines business processes. Refactored applications can trigger automated sequences across multiple systems, eliminating bottlenecks in traditional workflows. 

This integration typically involves converting fixed-format RPG codes into free-format versions that interact more effectively with automation frameworks. The result is improved process efficiency and reduced manual intervention in routine business operations. 

5. Secure Authentication Frameworks Integration

Security remains paramount in modern integrations. IBM iSeries consulting specialists implement robust authentication frameworks within refactored applications, including OAuth support and digital certificate implementation. 

These security measures protect API connections from increasingly sophisticated cyberattacks while ensuring appropriate access controls based on user roles and permissions. Businesses maintain data security while enabling necessary system connectivity. 

Best Practices Followed by iSeries Managed Services Providers During Refactoring 

Successful RPG code refactoring relies on proven methodologies that experienced iSeries managed services providers have refined through years of modernization projects. These best practices ensure quality outcomes while minimizing risks during the transformation process. 

1. Automate the RPG Refactoring Process 

Professional IBM iSeries consulting specialists utilize specialized tools rather than relying on manual code conversion. Rational Developer for IBM i (RDi) offers powerful features such as “Extract Procedure” that substantially automates the restructuring of legacy code. RDi’s refactoring capabilities eliminate much of the detailed manual coding previously required, encouraging developers to modernize more frequently. 

Automation tools analyze existing code structures and dependencies before suggesting transformations. This preliminary analysis identifies reusable components and pinpoints redundant code sections that can be streamlined. The actual conversion process applies consistent patterns across the entire codebase, ensuring uniformity in the refactored result. 

1. Incremental Refactoring to Reduce Bugs 

Every reputable IBM AS400 consulting company follows the golden rule of making small, incremental changes followed by immediate testing. This approach allows teams to isolate issues quickly when they arise. This methodology prevents the refactoring project from becoming unmanageable or drifting into an endless cycle. 

Each minor change maintains complete functional equivalence with the original code, preserving critical business logic while gradually improving the structure. When project priorities shift, teams can pause refactoring while still delivering value from completed improvements. 

1. Work with Testers to Ensure Refactoring Quality 

iSeries managed services providers emphasize testing throughout the refactoring journey. Effective collaboration with in-house testers enables AS400 consultants to perform baseline tests during and after refactoring, creating a reference point for comparing outcomes. Code coverage tools measure how thoroughly testing exercises the refactored applications. This comprehensive testing strategy ensures that modernized applications maintain complete functional equivalence with their legacy counterparts. 

Final Words 

RPG refactoring serves as the foundation for successful AS400 modernization without abandoning valuable legacy investments. Organizations that embrace strategic refactoring gain competitive advantages while preserving decades of embedded business logic within their systems. 

IBM iSeries services providers deliver strategic guidance that extends beyond technical code improvements. These specialists align refactoring efforts with business objectives while ensuring minimal operational disruption. Their methodical approach, utilizing automation tools, incremental changes, and comprehensive testing, reduces modernization risks significantly and drives AS400 operational efficiency.