STEP-NC in additive manufacturing: a comprehensive review, architecture, and data model proposal

Abstract In modern manufacturing, Digital Thread and Digital Twin technologies integrate and orchestrate data throughout the production lifecycle. To fully realize their potential, it is crucial to address challenges in data integration, management, and interoperability while enhancing system intelligence and contextual awareness. STEP-NC (STandard for the Exchange of Product model data - Numerical Control) emerges as a potential solution, enriching these digital systems with contextual information about products, processes, and machines. While STEP-NC has been extensively studied in machining, its application in Additive Manufacturing (AM) is still emerging. The current reliance on legacy formats like STL and G-code fails to meet the industry’s advancing needs. This work offers a comprehensive review of the current state of STEP-NC development for AM, highlighting a growing interest in its application, despite limited publications and advancements. To bridge these gaps, we propose STEP-NC entity definitions for managing data related to process parameters and operations in Fused Deposition Modeling (FDM) and Laser Metal Deposition (LMD) technologies. STEP-NC facilitates refined data management at the individual layer level, encompassing geometry, process parameters, material properties, and other key aspects. Additionally, we introduce a cyber-physical architecture for STEP-NC in manufacturing, aligned with the ISO 23247 framework. This architecture envisions a robust digital ecosystem driven by standards-based Digital Thread and Digital Twin technologies, with STEP and STEP-NC at its core, supported by essential open standards such as QIF, MTConnect, OPC-UA, and MQTT. By integrating contextual information, it enhances Digital Twin development for virtual monitoring, optimization, knowledge generation, and informed decision-making in manufacturing environments.