Research in engineering system evolution studies the technical performance (e.g., speed, capacity, and energy efficiency) and the functional and architectural changes of engineering systems (e.g., automobiles, aircrafts, laptops, and smartphones) over time. The research results of engineering system evolution help designers, R&D managers, investors, and policy makers to generate innovative design concepts, set reasonable R&D targets, invest in promising technologies, and develop effective incentive policies. In this paper, we introduce engineering system evolution as an emerging research area. We develop a cyclic model to understand the general structure of engineering system evolution and summarize seven basic research questions accordingly. A review and analysis of prior research related to engineering system evolution is provided to identify the pioneering works in this promising research area. We also discuss the challenges and opportunities in the quantitative and qualitative study of engineering system evolution for future research.