Modeling Mechanical Functional Architectures in SysML

Innovations in Cyber-Physical System (CPS) are driven by functionalities and features. Mechanical Engineering, on the other hand, is mainly concerned with the physical product architecture, i.e., the hierarchical arrangement of physical components and assemblies that forms the product, which is not explicitly linked to these functions. A holistic model-driven engineering approach for CPS, therefore, needs to bridge the gap between functions and the physical product architecture to enable agile development driven by automation. In the theoretical field of mechanical design methodology, functional architectures describe the functionality of the system under development as a hierarchical structure. However, in practice, these are typically not considered let alone modeled. Existing approaches utilizing mechanical functional architectures, however, do not formalize the relation between the functional architecture and the geometric design. Therefore, we conceived a meta-model that defines modeling-languages for modeling functional architectures of mechanical systems and physical solutions, i.e., interconnections of physical effects and geometries, as refinements of the functional components. We have encoded the meta-model as a SysML profile and applied it within an interdisciplinary, industrial project to model an automotive coolant pump. Our contribution signposts the potential of functional structures to not only bridge the gap between function and geometry in mechanics but also to integrate the heterogeneous domains participating in CPS engineering.