Reliability and availability performance as a tool to optimize power systems

The authors describe by means of a case study how the reliability and availability performance can be utilized to obtain the optimal solution for uninterruptible power supplies (UPS) from the power systems user´s point of view. It is concluded that UPS power systems cannot be optimized if the defined acceptable risk level is not well or not at all defined. In addition, it is noted that optimization is difficult or almost impossible if the reliability and availability performance philosophy and methods are not used or not understood