AS400 systems have been the backbone of enterprise operations for decades, offering stability and reliability. However, in today’s digital-first world, legacy applications struggle to keep up with business demands. CTOs face challenges such as increasing maintenance costs, integration difficulties, security vulnerabilities, and the need for enhanced user experiences.
Modernizing AS400 applications is no longer optional, but a business imperative. Organizations that delay modernization risk falling behind competitors, experiencing compliance issues, and losing operational efficiency. This guide dives deep into why modernization is necessary, the available strategies, and how CTOs can approach the transformation effectively.
The Business Case for AS400 Application Modernization
Risks of Legacy AS400 Applications
High Maintenance Costs: AS400 systems require specialized expertise, and finding RPG/COBOL developers is becoming increasingly difficult and expensive.
Limited Scalability: Businesses today demand agility, but legacy applications make it difficult to scale operations seamlessly, especially in cloud environments.
Security & Compliance Gaps: Outdated security protocols and unsupported versions make legacy systems a prime target for cyberattacks.
Poor User Experience (UX): Green screen interfaces lack the intuitive and modern usability that today’s workforce expects, impacting productivity.
Data Silos & Integration Challenges: Legacy applications often function in isolation, making it difficult to integrate with modern software like ERPs, CRMs, and data analytics tools.
Benefits of Modernization
Operational Efficiency: Upgraded systems reduce downtime and streamline business workflows.
Enhanced Performance & Scalability: Cloud-enabled AS400 applications can handle higher workloads while reducing infrastructure dependencies.
Better Security & Compliance: Modern architectures incorporate advanced encryption, multi-factor authentication, and automated compliance updates.
Future-Proofing IT Investments: Upgraded AS400 environments ensure long-term supportability, reducing the risk of forced migrations due to end-of-life hardware/software.
Improved Customer & Employee Experiences: Web-based interfaces, mobile-friendly applications, and AI-driven insights transform usability and engagement.
Also read: Legacy Code Modernization Made Easy with Automation
Key AS400 Application Modernization Strategies
Rehosting (Lift-and-Shift)
Involves migrating AS400 applications as-is to cloud or hybrid environments.
Best for: Organizations looking for quick wins without modifying core business logic.
Pros: Reduces infrastructure costs, improves disaster recovery options.
Cons: Doesn’t leverage cloud-native features; technical debt remains.
Refactoring (Code Optimization)
Improves existing RPG/COBOL code for performance gains without altering the application’s architecture.
Best for: Businesses that rely on AS400 applications but need better speed, efficiency, and maintainability.
Pros: Enhances performance, extends application lifespan.
Cons: Requires specialized AS400 development expertise.
Replatforming (Partial Modernization)
Moves AS400 applications to a new technology stack (e.g., Java, .NET) while preserving business logic.
Best for: Companies seeking a balance between cost and long-term flexibility.
Pros: Enables integration with modern tools while maintaining functionality.
Cons: Can be time-consuming and require retraining of IT staff.
Rebuilding (Full Transformation)
Completely redesigns AS400 applications using microservices and cloud-native architectures.
Best for: Organizations pursuing maximum agility, scalability, and future readiness.
Pros: Future-proofs IT systems, supports business innovation.
Cons: High initial investment, longer deployment time.
Key Technologies Powering AS400 Application Modernization
Cloud Enablement
Migrating AS400 workloads to the cloud (AWS, Azure, or IBM Cloud) provides elastic scalability, lower costs, and improved security. Hybrid-cloud models allow a phased approach to modernization.
API-Driven Connectivity
APIs bridge AS400 applications with modern software ecosystems, enabling real-time data exchange between legacy and cloud-based platforms.
Low-Code/No-Code Platforms
Modern low-code solutions enable enterprises to rapidly develop AS400-compatible web and mobile applications, reducing reliance on RPG developers.
AI & Automation Enhancements
Robotic Process Automation (RPA): Automates manual AS400 processes, reducing human errors and improving efficiency.
AI & Machine Learning: Extracts business insights from legacy AS400 data, enabling predictive analytics and automated decision-making.
Implement these today.
