Analyzing Early Requirements of Cyber-physical Systems through Structure and Goal Modeling

Integrating the computing process and the physical process, cyber-physical systems (CPS) pose many challenges to the system analysis and modeling. While most of the existing work focuses on developing the precise and formal model of CPS, little attentions have been given to the early requirements analysis and modeling which focuses on what the users' requirements are and what the software and physical domains of CPS will do to meet the users' requirements. In this paper, we provide an approach for early requirements analysis and modeling of CPS. This approach proposes to build the structure model to capture the system architecture, and the goal model to capture the refinement relationships between the users' requirements and the assumptions and requirements on the domains in CPS. These models help to build a clear understanding about CPS between the users and the designers and pave the way to define the precise and formal model. What these models are and how to build them are illustrated through a cruise control system.