 This paper examines dynamic power management, DPM, a technique used to design low-power and energy-efficient nodes for wireless sensor networks. It models the behavior of an input event arrival using a first-in-first-out, FIFO, Q and a single server. The authors then develop an event-driven sensor node based on a semi-Markov model. They analyze how changes in the event arrival rate and probability of change detection affect the performance of the node. The results show that as the event arrival rate increases, so does the server utilization, leading to increased power consumption and reduced lifetime. Additionally, when the probability of change detection increases, it leads to higher power consumption and shorter lifetime. This article was authored by Rocky Kalamani and Shridhar Ayer.