Arecurring criticism of the Uptime Institute’s Tier Classification System was that it did not do enough. There are aspects of a data center operation-critical to ongoing uptime-that the four tiers are silent upon.
When developed in the 1990s, the tiers filled a specific need. “At that time, there was no grading criteria or performance standard for data center,” explains Pitt Turner, Uptime Institute executive director and Tier Classification System co-author. “The tiers started with the request of an owner in growth mode through M&A. When the executives walked through a new data center, they were sure they had a ‘great’ new data center. Tiers were developed to fill this need-to help educate executives that just because a computer room has clean raised floor does not mean it meets the business needs. Tiers were created to establish a simple and clear way to differentiate the increasing functionality of data center site infrastructure. The tier standard is now the international reference for data center performance” (see figure 1).
On July 1, 2010, the Uptime Institute substantially expanded tiers to address additional fundamentals of data center uptime. This expansion was necessary because the tiers guide the design, construction, and commissioning of a facility, but those are only the beginning of developing a successful data center: the beginning of an unrelenting endeavor from day one of operations to obsolescence of the data center.
Operational sustainability is a language and rating system that complements the four tiers with focus on the operation of the data center infrastructure. “Poor operations are more important than the tier of the design because they can defeat even a fault tolerant infrastructure. Operations are the showstopper at any data center,” states Vince Renaud, co-author of both the tier and operational sustainability standards. Before elaborating on the development and focus of operational sustainability, it is important to re-affirm the intent and use of the Tier Classification System.
The greatest vulnerability of the tiers is to strip them of business case. The ‘work’ of the tiers is to align an organization’s tolerance (or intolerance) for downtime and its infrastructure solution. Divorced from business case, the tiers are subjective. Misapplication of the tiers as an adjectival rating system (good-better-best) is a use inconsistent with its intent. Misuse of the tiers results in a design solution that is temporary or meaningless in terms of business value. In other words, knives make short-lived screwdrivers.
Used effectively, the tiers are protection against penalty and pain. The cost of downtime in both real dollars and incalculable adverse effects drives infrastructure investment. Selection of a response tier results from diligent investigation assessment into the owner’s reliance on its data center to continue to be profitable.
Calculating downtime is crucial to the use of the tiers and is sometimes shorted even by the largest IT-centric organizations. This is a considerable effort that requires cash, staff, and months to complete. The cost of downtime is the lynchpin of the justification for a data center and its performance level. Calculating this cost involves investigation into the IT needs of the various data center clients, whether internal or external. Then, the clients must be brought to consensus on the penalties that the organization will endure for planned or unplanned outages. The anticipated hurt will be both tangible and intangible: lost revenue, fines, sagging share value, adverse market perception, and increased regulatory attention.
Ignoring these tasks can lead to a tier decision based on subjective criteria. For example, the Uptime Institute regularly encounters data center projects that are justified in terms of pride of ownership (e.g., world class, gold-plated). If the infrastructure investment is based on the ‘best’ outside the content of business requirements, the project will be cancelled or shrunk when submitted to a rigorous analysis by its internal or external oversight. This holds true for enterprise or colocation data centers.