The paper "Cyber Physical Systems: Design Challenges" by Edward A. Lee discusses the integration of computation and physical processes in Cyber-Physical Systems (CPS). CPS are systems where embedded computers and networks monitor and control physical processes, often with feedback loops. The economic and societal potential of CPS is vast, but significant challenges exist due to the unique requirements of physical components, which differ from general-purpose computing. The paper highlights that current computing and networking technologies may not provide an adequate foundation for CPS, as they lack temporal semantics and adequate concurrency models, making real-time performance difficult. The author emphasizes the need for predictable and reliable software in CPS, especially in safety-critical applications. He argues that while components should be made predictable and reliable if technologically feasible, robustness must be built into higher levels of abstraction when this is not possible. The current abstractions in computing and networking, such as method calls and threads, do not effectively address the timing and concurrency issues in CPS. To address these challenges, the paper suggests that fundamental changes in computing and networking abstractions are necessary. These changes should embrace physical dynamics and computation in a unified way. The author proposes bottom-up approaches, such as modifying computer architectures to deliver precise timing, and top-down solutions, such as model-based design, which uses models to synthesize software. The goal is to create semantic models that reflect the properties of both software and physical processes, enabling more effective orchestration and addressing the unique challenges of CPS.The paper "Cyber Physical Systems: Design Challenges" by Edward A. Lee discusses the integration of computation and physical processes in Cyber-Physical Systems (CPS). CPS are systems where embedded computers and networks monitor and control physical processes, often with feedback loops. The economic and societal potential of CPS is vast, but significant challenges exist due to the unique requirements of physical components, which differ from general-purpose computing. The paper highlights that current computing and networking technologies may not provide an adequate foundation for CPS, as they lack temporal semantics and adequate concurrency models, making real-time performance difficult. The author emphasizes the need for predictable and reliable software in CPS, especially in safety-critical applications. He argues that while components should be made predictable and reliable if technologically feasible, robustness must be built into higher levels of abstraction when this is not possible. The current abstractions in computing and networking, such as method calls and threads, do not effectively address the timing and concurrency issues in CPS. To address these challenges, the paper suggests that fundamental changes in computing and networking abstractions are necessary. These changes should embrace physical dynamics and computation in a unified way. The author proposes bottom-up approaches, such as modifying computer architectures to deliver precise timing, and top-down solutions, such as model-based design, which uses models to synthesize software. The goal is to create semantic models that reflect the properties of both software and physical processes, enabling more effective orchestration and addressing the unique challenges of CPS.