ARCHITECTURAL APPROACH TO MINIMIZING CORE MODIFICATIONS IN CORPORATE INFORMATION SYSTEMS

Abstract

Enterprise resource planning (ERP) systems that have been in operation for many years typically accumulate a significant number of custom extensions embedded directly into the system core. While such modifications provide short-term business flexibility, they accumulate technical debt, impede upgrade processes, and increase risks associated with transitioning to modern ERP architectures. In response, SAP SE introduced the Clean Core strategy for SAP S/4HANA, which promotes preservation of the standard ERP core and recommends implementing application-specific logic outside the core using cloud extensibility. Although originally intended for new-generation platforms, the underlying architectural principles of Clean Core can also be adapted to legacy environments. This paper proposes an architectural approach that enables gradual reduction in the volume of core modifications in existing ERP systems by separating standard functionality and externalized extensions. The approach is demonstrated on an SAP ECC 6.0 landscape integrated with SAP Business Technology Platform (SAP BTP). Application-specific logic is relocated to the ABAP Environment on SAP BTP and interacts with the ERP system through service-oriented interfaces implemented via the OData protocol. The Service Consumption Model serves as the key mechanism for consistent and type-safe consumption of remote services and integration with the RAP programming model. A mathematical model for quantifying the volume of core modifications is introduced to formalize the minimization objective. The model enables calculation of a relative effectiveness indicator ∆M, which measures the reduction of core modifications following the transition to the proposed architecture. A numerical example and a comparative graph illustrate the dynamics of modification volumes over several years, both with and without the architectural approach. The obtained results indicate that the proposed approach contributes to controlled modernization of legacy ERP systems by mitigating upgrade risks, reducing technical debt, and preparing the system landscape for migration to contemporary ERP platforms. The research results can be used by organizations operating mission-critical ERP environments, particularly in energy and infrastructure sectors, to plan their transition roadmap toward Clean Core principles without disruptive system replacement.