Uptime Institute answered questions submitted during the "Intro to Tiers Classification System Webinar" in the new Tier Program email series.
Q: Will the runtime limitations of the generators mandated by Air Permits affect the tier rating requirements?
Tiers is not a one size fits all, but allows for many ways to meet the criteria. You and your team determine the best solution for your project.
Uptime Institute encountered the following Tier Myths and Misconceptions, published on 24 March 2010, during recent site visits in Latin America, Europe, Russia, Africa, and Asia. These myths have taken attention away from the fundamental concepts of the Tier Classification System. The result has been shortfalls in design topology despite adequate budgeting. These shortfalls put the data center's ongoing uptime at risk. Although encountered more often internationally, the myths below have also been noted in North America.
Uptime: The similarities between the Uptime Institute Tiers and TIA-942 stop at the surface. Uptime Institute Tiers is functionally disconnected from TIA-942. The core objective of Uptime Institute Tiers is to guide a design topology that will deliver high levels of availability -- as dictated by the owner's business case. Uptime Institute Tiers evaluates data centers by their capability to allow maintenance and to withstand a fault. Uptime Institute Tiers is not available in checklist form. To avoid further confusion, Uptime Institute recommends Roman numbers (I, II, III, IV) to signify Tier-based projects.
Myth:Uptime Institute Tiers is U.S.-centric.
Uptime: The Uptime Institute is currently delivering Tier Certifications in over 25 countries. During the design and construction of these projects, there has not been a conflict between Tiers and local building codes, statutes, or jurisdictions. Tiers, which allows for many solutions and a variety of configurations, gives the engineering and operations team the flexibility to meet both the local regulations and the performance requirements.
Myth:Uptime Institute Tiers requires an EPO.
Uptime: Analysis of the Uptime Institute's Abnormal Incident Report database reveals that accidental EPO activation is a recurring cause of downtime. Uptime Institute Tiers does not mandate an EPO. Unless compelled by a local jurisdiction or code, Uptime Institute does not recommend EPO installation. However, if an EPO is installed, it must also incorporate the Concurrent Maintainability or Fault Tolerant objectives, as specified by the owner.
Uptime: The choice of underfloor or overhead cooling is an owner decision based an operational preference. In Uptime Institute experience, a raised floor enhances operational flexibility over the long term. Yet, decisions such as raised floor or on-slab, Cold Aisle/Hot Aisle, containment of Cold/Hot Aisles, and gallery cooling can affect the efficiency of the computer room environment, but are NOT mandated by Uptime Institute Tiers.
Myth:For Tier III and IV, the engine-generator plant must be operational at all times.
Uptime: Data centers will utilize the public electrical utility a majority of the time. However, the engine-generator plant must be properly configured and sized to carry the critical load without runtime limitations. Meeting this criteria requires special attention to the engine-generator capacity ratings and the feeds to the engine-generator plant. In all cases, Uptime Institute Tiers does not require that the engine-generator plant run at all times.
The Uptime Institute has recently released two Accredited Tier Designer Technical Papers. These papers, part of an ongoing series, provide technical clarity on the Tier consequences of specific subsystems. The topics, makeup water source and engine-generator ratings, were identified as areas of concern by attendees from over 13 countries at the 2010 Accredited Tier Designer sessions.
The following Tier Myth and Misconception, published on 29 October 2009, addresses the commonly held belief that Tier dictates infrastructure physical security. Tier requirements address the functionality of the data center design topology; Operational Sustainability addresses the risk factors beyond design topology, including infrastructure physical security.
Myth:Re-enforced perimeter fencing is required for Tiers III and IV.
Myth:Physical security measures for outdoor critical equipment (e.g., fuel storage tanks) are a Tier requirement.
Myth:CCTV is required for Tiers III and IV.
Uptime: The Tier Classification System does not prescribe security provisions. Nevertheless, these infrastructure physical security risk factors should be specifically and thoroughly addressed in the owner’s Operational Sustainability requirements.
The level of security is largely determined by industry, the criticality of the IT function performed on site, and the owner’s policies. For example, a financial institution will typically invest in a level of security exceeding that of an academic institution.
There are numerous infrastructure physical security measures which are best practices, regardless of Tier. These include biometric readers, bollards, guard houses, hiding in plain sight, mantraps, re-enforced perimeter fencing, video surveillance, etc. Best practices are critical in reducing the risk exposure of curiosity, mischief, crimes, and accidents. However, best practices should not be confused with Tier requirements.
In order to maintain focus on the Tier requirements, the Uptime Institute has published Tier Standard: Topology, which places the Tiers in a standards format to facilitate practical application. This document puts aside the attributes and illustrations that can lead to confusion. Tier Standard: Topology is available for download.
The following three myths, published on 21 September 2009, finish the discussion begun by Digital Realty Trust's video "Myth of the Month: The Tier System."
Myth:Tiers do not address business requirements.
Uptime: The Tiers are a performance-based, business-case-driven data center benchmarking system. An organization's risk tolerance determines the appropriate Tier for the business. In other words, the Tiers are predicated on the business case of the individual company. Without determination of a unique business case, organizations are misusing the Tiers and bypassing the internal dialogue that needs to occur.
Myth:Tier II provides Concurrent Maintenance opportunities.
Uptime: Tier II ensures redundant capacity components, but requires a shutdown of the computer room for planned maintenance or replacement of critical equipment. The fundamental concept of Tier III is Concurrent Maintenance functionality. Digital Realty Trust asserts the following: "Concurrent Maintainability is actually one of the most important driving design characteristics that you need to have inside your data center. You need to be able to maintain your facility while it's running, regardless of if it's a Tier IV to a Tier II design." Digital Realty Trust mentions Tier II and IV solutions, but disregards Tier III. The requirement to maintain infrastructure without shutting down equipment, known as Concurrent Maintainability, defines Tier III. Many owners' business cases, including healthcare, domestic outsourcers, and state governments, require Tier III. The list of organizations that have protected their investment with Tier III Certification may be found HERE.
Myth:Nobody needs a Tier IV data center.
Uptime: Many owners' business cases require Tier IV, including banking/financial; insurance; outsourcers in UK, Middle East, and South Africa; and federal and provincial governments. (List of Tier IV Certifications may be found HERE.) The Tiers are not prescriptive. Tier IV is not the best answer for all organizations, neither is Tier II . Experience dictates that owners perform due diligence assessments of their own and outsourcers' facilities to address the following: If the facility is Tier II and by definition does not include Concurrent Maintenance capabilities across all critical subsystems, a) can the business tolerate a maintenance-related shutdown and b) how does the site operations team propose to coordinate a maintenance-related, site-wide shutdown across 10s or even 100s of data center clients?
The following four myths were published on 27 August 2009.
Uptime: The number of utility feeds, substations, and grids that provide public power to the facility neither predicts nor influences Tier.
Uptime: N+1, N+2, S+S, or 2(N+1) does not determine Tier.
Uptime: Tier Certification is a third-party, independent assessment to the Uptime Institute's Tier Classification System, performed by its Professional Services consultants.
Uptime: Although a critical consideration for the lifecycle operation of the facility, geographical location does not affect Tier.
Tier Myths and Misconceptions
As part of the Tier Program, Uptime Institute and Uptime Institute Professional Services address Tier Classification System Myths & Misconceptions prevalent in the industry.