The chapter discusses the rapid integration of cyber-physical systems (CPS) into critical infrastructure, health systems, defense capabilities, manufacturing processes, and personal property. It highlights the importance of modeling and simulation in balancing enthusiasm and caution, addressing the complexities and challenges associated with CPS. The author, Kris Rosfjord from The MITRE Corporation, touches on three key topics: timescale challenges, conceptual expectations, and workforce shortages. Timescale challenges involve managing the varying lifetimes of components, from industrial parts with a lifespan of decades to software with a lifespan of months. The need for reliability, safety, scalability, and adaptability exacerbates these challenges. The chapter also discusses the limitations and expectations of automated CPS, emphasizing the importance of understanding the decisions made by these systems and the need for explainability and robustness. Finally, the chapter addresses the workforce shortage, noting that while there has been a modest increase in graduate degrees in relevant fields, the demand for experts in math, computer science, physics, psychology, and engineering remains high. The text aims to foster the development of expertise in modeling and simulation for CPS, offering a cross-disciplinary perspective to address these challenges.The chapter discusses the rapid integration of cyber-physical systems (CPS) into critical infrastructure, health systems, defense capabilities, manufacturing processes, and personal property. It highlights the importance of modeling and simulation in balancing enthusiasm and caution, addressing the complexities and challenges associated with CPS. The author, Kris Rosfjord from The MITRE Corporation, touches on three key topics: timescale challenges, conceptual expectations, and workforce shortages. Timescale challenges involve managing the varying lifetimes of components, from industrial parts with a lifespan of decades to software with a lifespan of months. The need for reliability, safety, scalability, and adaptability exacerbates these challenges. The chapter also discusses the limitations and expectations of automated CPS, emphasizing the importance of understanding the decisions made by these systems and the need for explainability and robustness. Finally, the chapter addresses the workforce shortage, noting that while there has been a modest increase in graduate degrees in relevant fields, the demand for experts in math, computer science, physics, psychology, and engineering remains high. The text aims to foster the development of expertise in modeling and simulation for CPS, offering a cross-disciplinary perspective to address these challenges.