Comparison of Availability and Resiliency Planning for Critical Loads

This paper discusses fundamental notions for planning resilient and reliable powering of critical loads, such as information and communications technology (ICT) sites, and compares strategies for such purpose. In particular, this paper explains the fundamental differences between higher availability and higher resilience planning beyond the basic common notion that the former applies to normal operating condition and the latter for uncommon extreme events. Implications of these differences are also explored. Additionally, this paper explores how to take into consideration adaptation and planning activities for higher availability or higher resilience. In order to support this discussion this paper makes use of a model representing the effects of gensets refueling processes on availability and resilience. Uncertainty costs involved in these planning processes are, then, explored. Relationships between reliability and resilience planning are also discussed.