Citation:

Shiva Kumar Devasani, 2026. Modernizing AS/400-Based Enterprise Systems: A Practical Framework for Retail and Banking Transformation  Volume 6 Issue 3: 07-14.

Abstract:

For more than 30 years, the IBM AS/400 (iSeries/IBM i) platform has supported mission-critical operations in retail and banking with unmatched reliability, seamless database management, and high performance. These legacy environments, however, are under tremendous strategic pressure amid the rapid pace of digital transformation, cloud-native architectures, and the demands of the API economy. In this paper, an in-depth, evidence-based approach is presented to modernize enterprise systems built on the AS/400 platform, supported by case studies of 12 retail chains and 8 banking institutions from North America and Europe. We analyze four modernization strategies, encapsulation, re-platforming, re-architecting, and full replacement, and compare the strategies on cost, risk, talent availability, integration complexity, and time-to-value. The results we've seen suggest that using a hybrid strategy, with some workloads moved to the cloud and the remainder wrapped in APIs, offers the best risk-reward ratio for most organizations. We also suggest a cloud migration lifecycle and a prioritized risk-mitigation process that has been tested in practice. The paper then provides industry-specific suggestions for retail and banking, covering regulatory compliance, real-time analytics enablement, and organizational change management.

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Keywords:

AS/400 Modernization, IBM I, Legacy Systems Transformation, Enterprise Architecture, Retail IT, Banking Systems, Cloud Migration, API Integration, Digital Transformation, RPG Modernization.