MetaFactory: A cloud-based framework to configure and generate dynamic data structures from the STEP-NC knowledge graph

In our previous studies, twin-oriented manufacturing has been identified as a crucial solution to address the manufacturing crisis. Within this context, the notion of “digital twin as a service” necessitates that various twin services share and communicate with each other in a standardized manner. STEP-NC offers a potentially unified model to facilitate data exchange, providing object-oriented and standardized data models for a comprehensive representation of manufacturing resources in the digital realm. However, the complexity of STEP-NC renders it too cumbersome for implementation in diverse cloud-based services or PC-based software. This complexity is a fundamental reason why STEP-NC has struggled to find application in commercial CNC systems despite years of research. To overcome this technical challenge, this paper introduces a novel concept termed “dynamic STEP-NC data structure”, inspired by the dynamic language philosophy of dynamic programming language (such as Python). This approach allows different services and software packages to maintain their own data definitions while still aligning with the original STEP-NC definition. We have developed a framework called MetaFactory that supports the configuration of streamlined data structures and generates the corresponding program code required by various service developers. On this basis, we implemented automatic modeling for a STEP-NC object-oriented database. Using the data trimming and dimensionality reduction methods provided by MetaFactory, several prototype systems for different application scenarios have been developed.