Marketeers have hijacked Uptime Institute's Tier system for assessing data centre availability and could overcomplicate it to the point of ruin, said one of the industry's top engineers at DatacenterDynamics London this week.

Mike Manos, vice president of technical services at Digital Realty Trust, warned that the foundation for comparison of data centres is being eroded. "Tier names have been co-opted by the marketing community and away from engineers," he said.

It's like PUE all over again, Manos told the audience during a panel session. "The marketing guys have run away with our system." The tier system should be an engineering concept and its strength is its simplicity, Manos said. Marketing managers who think up variations on the four classic pillars of measurement (such as Tier 2a) risk trivializing the system's advantages.

Interxion VP Lex Coors said the Uptime tier classification is still actual. Persons in the industry are now saying Tier 3 plus or Tier 4 minus, this does not exist. Uptime is very clear: the weakest link determines the Tier class, a Tier 3 cooling system with a Tier 4 electrical system is not Tier 3 plus or equal to Tier 4 - but Tier 3. Persons not using the Tier class as they design their data centers according to their special needs could still verify what Tier class they actually have built. So, the The Uptime Tier classification is still very actual."

Not everyone agreed, however.

Ed Ansett, MD of EMEA for HP Critical Facilities Services, said the classification system was a "gross oversimplification" of characteristics of highly complex facilities.