A Mechanism-Based Theory of Legacy Enterprise Information System Reconfiguration in Incumbent Firms

How can incumbent firms reconfigure their legacy Enterprise Information Systems (EIS) for enterprise renewal? We address this question by developing an empirically grounded, mechanism-based theory of legacy EIS reconfiguration in incumbent firms that reconciles two opposing perspectives in IS research: legacy EIS as sources of technical debt that constrain agility, and legacy EIS as installed bases that can be leveraged for digital reinvention. Specifically, we draw on findings from a multiple-case study of five German incumbent manufacturing firms to identify four generative mechanisms through which incumbent firms leverage operational stability of their legacy EIS for digital pilots, activate historically accumulated data through analytics, augment legacy EIS with middleware interfaces, and retrofit legacy EIS for recurring revenue models. When enacted, these mechanisms reconfigure legacy EIS into ambidextrous EIS landscapes that preserve operational stability through contained and selectively reduced technical debt, while expanding potential options for future digital initiatives. We conclude by outlining actionable guidance for practitioners and a research agenda on how legacy EIS reconfiguration, rather than replacement, can serve as a foundation for enterprise renewal.