Data centers are classified into four tiers under the Uptime Institute’s data center classification system. The Uptime Institute is a professional organization devoted to improving the performance, efficiency, and reliability of business-critical data center infrastructure. Each tier represents a different level of fault tolerance.

It is important to note that this is a grading system that is helpful to use to determine the level of risk an organization is willing to accept regarding the availability of data center infrastructures.

The tiers are labeled 1, 2, 3, or 4 displayed in Roman Numerals I, II, III, and IV based where the higher the number indicates a more robust and fault-tolerant facility in terms of redundancy, availability, and downtime. The tiers are progressive meaning that Tier II will meet all the criteria of Tier I and meet the additional Tier II criteria, Tier III will meet all the criteria of Tiers I and II and additional criteria for Tier III, and Tier IV includes all the criteria of Tier I through III plus additional criteria for Tier IV.

 Here's a brief description of each tier and its attributes:

Tier I: Basic Capacity

Redundancy: N

Availability: 99.671%

Downtime: 28.8 hours per year

A Tier I data center provides a basic infrastructure with a single, non-redundant distribution path serving the IT equipment. In other words, there is one piece of equipment and if it goes down, there is no built-in backup system. Further, there's no built-in redundancy for its power, cooling, network links, storage, and server equipment. This means if any piece of equipment fails or needs maintenance, the entire data center might be shut down. Further, Tier 1 data centers must completely shut down for routine maintenance which is usually done outside of normal business hours.

Tier I is the simplest and least expensive type of data center to build and maintain, but it also has the most downtime. For many healthcare systems and practices a Tier I data center carries too much risk of downtime and is not the best option for organizations that need 24/7/365 uptime.

Tier II: Redundant Capacity Components

Redundancy: N+1

Availability: 99.741%

Downtime: 22 hours per year

Tier II data centers include redundant components to improve their reliability compared to Tier I. Key infrastructure components power, cooling, network links, storage, and servers have at least one spare, so if one fails, the spare can take over. The additional components of a Tier II data center include:

• • • • -   Engine generators
      • -  Energy storage
      • -  Chillers
      • -  UPS modules
      • -  Pumps
      • -  Heat injection equipment
      • -  Fuel tanks
      • -  Fuel cells
        

However, the distribution paths are still single and non-redundant, so the data center might need to be shut down for maintenance. While an improvement over Tier I, there is still part of the infrastructure for which there is no real-time backup. This means that unexpected shutdowns can occur. This is a solid option for a small organization that might not have the ability to pay for a more robust data center. For larger healthcare systems and practices a Tier II data center carries too much risk of downtime due to an unexpected failure.

Tier III: Concurrently Maintainable

Redundancy: N+1

Availability: 99.982%

Downtime: 1.6 hours per year

Tier III data centers are designed to remain fully operational even during maintenance activities. Like Tier II data centers key infrastructure components power, cooling, network links, storage, and servers have at least one spare, so if one fails, the spare can take over. But in addition, Tier III data centers have the addition of multiple redundant paths. If a component or path fails, operations can continue without interruption on the remaining paths.

This is a major advantage of a Tier III data center over Tier I and II data centers because of the low risk of downtime. This is because Tier III data centers have redundant paths to serve the critical infrastructure, if one path fails the data center routes to another path. Redundances in Tier III data centers include:

• -  Multiple power disruption paths
• -  Multiple cooling paths
• -  Increased number of power backup sources
• -  Specific procedures allow for maintenance and repairs without disruption of service.
• -  Power outage protection

Further, Tier III data centers don’t require shutdowns for routine maintenance or repairs. Any part of a Tier III data center can be shut down with no impact on IT operations resulting in little to no disruptions in service. For this reason, many healthcare systems and practices choose Tier III data centers.

 Tier IV: Fault Tolerant

Redundancy: 2N+1

Availability: 99.995%

Downtime: 26.3 minutes per year

Tier IV is the highest level of the data center, designed to be fully fault-tolerant, every piece of equipment is duplicated plus the entire infrastructure is redundant. Tier IV data centers have multiple, independent, physically isolated systems providing power, cooling, network links, storage, and servers. This means a failure in one system - whether due to a component failure, human error, or even a fire or flood - won't disrupt service. It would take every piece of equipment in the data center to fail for a Tier IV data center to experience a service disruption. Tier IV data centers are the most reliable but also the most expensive to build and operate. Tier IV data centers are the most reliable; however, that reliability comes with a price as they are more than double the cost of a Tier III data center.

In conclusion, picking the right Tier data center involves weighing the risk, cost, and benefits of fault tolerance vs. cost. Higher-tier data centers are more expensive to build, maintain, and operate. For this reason, many organizations weigh their need for full fault tolerance against their available budgets before deciding on the tier of data center they require.

About iShare Medical 

iShare Medical is the trusted online platform for securing, sending, and sharing medical information among patients, providers, and payers. iShare Medical provides bi-directional sharing of medical data across our nationwide network of 2.8 million healthcare delivering data to the provider at the point of care to the patient's chart inside of their EHR.

iShare Medical is EHNAC Accredited for Privacy and Security and one of only a handful of companies to be a DirectTrust Accredited Trust Anchor HISP (Health Information Services Provider).

iShare Medical operates in two Tier III data centers, one located in Kansas City, Missouri, and the other located in Des Moines, Iowa.