This paper presents the Just in Time/Just Enough Energy Management (JEM) methodology that is applicable to a broad range of computing systems. The conventional concept of a fixed voltage supply (V DD ) scheme for both performance and power saving modes of computing systems is revisited and is improved with JEM. The JEM consists of an efficient DC/DC converter and a Power Management Integrated Circuit (PMIC) with a feedback to monitor the activities within a given computing system, providing a new means for dynamic voltage scaling at the system level. The JEM is tested and validated on a blade server that results in 15.11 percent power savings at the motherboard level. A significant thermal improvement of 9.0 C is measured in a 16 GB memory module of the blade server, as well. Moreover, a JEM enabled CMOS circuit depicts a remarkable reduction in the supply current. Furthermore, the JEM is compared to a conventional power supply design, with significant improvement in the processor performance and considerable power savings in the blade server.