Kudritzki, a vice president with the Uptime Institute, travels to South America, Europe and other regions explaining the tier system to prospective clients and supporting them while they get certified. This year he's opening an Uptime office in Sao Paulo.

The according to their expected levels of uptime and availability, based on how much redundancy is built into the infrastructure. A Tier 3 data center has a high level of uptime, and a Tier 4 is about as bulletproof as they come.

One of the trends Kudritzki has seen is more businesses asking their collocation facility or managed hosting provider to become tier-certified. As businesses start to put more applications in third-party data centers, the tier system can provide them with assurance that they're getting the level of service they pay for, he said.

One week before the Institute's , Kudritzki talked to IDG News Service about this and other trends. Following is an edited transcript:

IDG News Service: What's the purpose of the tier system, why is it useful?