A four tier system that provides a simple and effective means for identifying different data center site infrastructure design topologies. The Uptime Institute's tiered classification system is an industry standard approach to site infrastructure functionality addresses common benchmarking standard needs. The four tiers, as classified by The Uptime Institute include the following:

• Tier 1: composed of a single path for power and cooling distribution, without redundant components, providing 99.671% availability.
• Tier II: composed of a single path for power and cooling distribution, with redundant components, providing 99.741% availability
• Tier III: composed of multiple active power and cooling distribution paths, but only one path active, has redundant components, and is concurrently maintainable, providing 99.982% availability
• Tier IV: composed of multiple active power and cooling distribution paths, has redundant components, and is fault tolerant, providing 99.995% availability.

Bringing Manageability to the Data Center
Every day, consumers and businesses around the world benefit from computerized, web-based services and transactions, thanks to data centers. Data centers house the computing, data storage, and networking equipment that make routine tasks faster, easier, and more accurate.

Processor: How's & Why's Of Data Center Tiers
When it comes to data centers, being No. 1 is not the best. Data centers typically are ranked in tiers, with Tier I the most basic and prone to downtime and Tier IV the most robust, redundant, and functional.

Site Infrastructure Tier Certification
The specifications listed on this web page have been established by the fifty-one members of The Uptime Institute's Site Uptime Network. These specifications pertain to all computer and communication equipment critical to maintaining uninterrupted information availability.

The Uptime Institute, Inc.
Using benchmarking, abnormal incident data, and industry Best Practices collected from members of its knowledge communities, The Uptime Institute, Inc. (The Institute) has distilled uptime management into scientific disciplines and practices which can be confidently applied.