Enterprise Resource Planning (ERP) systems like SAP are widely used to manage engineering and maintenance tasks. They help with scheduling maintenance, managing spare parts, and tracking work orders. However, these systems are centralized, which can lead to issues with trust, data security, and audit accuracy—especially when multiple companies are involved. This paper proposes adding a blockchain layer to ERP systems to address these issues. The blockchain records maintenance activities in an unchangeable format, tracks the origin of parts, and uses smart contracts to automate compliance and service agreements. Data flows between the ERP and blockchain through APIs, and IoT sensors can trigger actions in real time. This approach improves transparency, reduces the risk of data tampering, and makes audits easier. Early results show that it can strengthen trust between stakeholders and improve regulatory compliance without replacing existing ERP functions.