The Uptime Institute has released the latest update of the Tier Standard: Topology effective 1 January 2018. This 2018 update to the Standard specification (previous update was dated 2012) is the result of more than five additional years of real-world data center experience and additional application notes associated with the use of newer technologies found in many recent data centers. The 2018 update to the Tier Standard : Topology reflects the experience drawn from organizations completing Uptime Institute’s Tier certification and additional experience gathered by Uptime Institute Professional Services during the conduct of its professional services portfolio. Mostly clarification to eliminate any ambiguity as well as providing additional context in nature, the 2018 update to the Tier Standard : Topology clarifies the intent of Uptime Institute regarding a number of topics, including; the need for on-site power generation, definitive ambient temperature ranges, a recommendation on communications entries, and makeup water for evaporative cooling systems.