CUBES, the next-generation spectrograph for VLT: a comprehensive MBSE approach to the project development. Focus on requirements management, activities modeling, PBS, and BoM automatic generation

Lately, the Italian astronomical community has begun the transition to Model Based System Engineering (MBSE). This tool has been largely applied to the development of the Cassegrain U-Band Efficient Spectrograph (CUBES) designed to provide high instrumental efficiency ( > 37 %) observations in the near UV (305-400 nm requirement, 300-420 nm goal) at a spectral resolving power of R > 20, 000 (with a lower-resolution, skylimited mode of R ≈ 7, 000). Here, MBSE has been used mainly in 3 areas: requirements management, activities modeling, and generation of system structure documents, like the Product Breakdown Structure (PBS) or the Bill of Materials (BoM). Requirements management controls the flow-down process to have a coherent list of requirements. This is achieved using derived properties and tailored numbering. Activities modeling uses traditional MBSE techniques while mimicking the software templates for calibration and observation. To generate structural documents, the system structure is generated in Cameo using the outputs from the subsystems, granting high coherency between the model and the actual design state. The interaction with non-Cameo users relies on Excel files, accessible to all interested parties and usable by Cameo to export and import information.