TIER Classification: learn about its importance for Data Centers

What do you take into account when hiring a data center service for your business? If TIER Classification is at the top of your list, you can be sure it will be a great investment.

After all, interconnection between resources and digital environments is one of the requirements for companies seeking success. A robust and available data infrastructure which ensures information security and high performance is crucial.

However, the search for a data center provider that delivers that has to look beyond cost. The company must follow rigorous international standards, capable of validating and measuring its quality of service.

And this is exactly what TIER Classification provides, a label that lets your company know exactly what the provider can deliver. So, before investing in a data center, it’s essential to understand more about TIER Classification. This content covers everything on the topic. Ready to learn more?

TIER Classification: what is it?

TIER Classification is a type of certification that aims to validate the performance and reliability of data center infrastructures. It’s a system created more than 25 years ago and still being currently applied by the Uptime Institute.

The set of guidelines (ANSI/TIA/EIA-942) defines mechanical, electrical, architectural, and communication parameters for the optimal performance of data centers.

The TIER classification is independent of size, and rates aspects such as availability and performance to help companies direct their investments. Thus, once you know the TIER classification of providers, you can have a quick idea of what they can deliver — that is, whether or not they are able to meet your demands.

It’s worth mentioning that “tier” is a word with English origins, meaning “layer” or “level.” Thus, the TIER Classification has different levels of certification: TIER I, TIER II, TIER III, and TIER IV.

Uptime Institute lists some of the most critical points to be assessed:

Performance based: the project must meet the requirements of availability, redundancy, and fault tolerance.

Technology Neutral: the TIER Classification does not require or rely upon standard technologies, remaining open to innovation.

Supplier independence: there is no relationship or dependency between the institute and suppliers.

Flexible: the company is free to comply with local guidelines.

Life cycle: certification seeks to validate all data center requirements.

Certification: certification is independent, provided by expert engineers.

Naturally, the higher the TIER, the more robust the data center infrastructure.

How the TIER classification system works

Only the Uptime Institute can be consulted for a TIER Classification, and it is the only institution authorized to issue certificates. Therefore, there are very strict controls in place, based on international guidelines and standards.

There is no specific regulatory standard applicable to TIER Classification in Brazil, but the system is used together with some other regulations (such as NBR 5410, NBR 15247, NBR 27002, and NBR 11515).


TIER I is the simplest of the Classification levels.

Here, the company is certified to operate servers that follow basic compliance criteria, with no redundant components. It has an air conditioning system, as well as electrical distribution subsystems.

At TIER I, the infrastructure has availability to process about 99.671% of applications. It faces up to 28.8 hours of downtime per year. In addition, it must be completely shut down annually once a year for preventive and corrective maintenance.


TIER II automatically meets the above requirements.

It’s worth mentioning that this is a certificate that validates the presence of a partially redundant infrastructure. It’s more aimed at small businesses, whose infrastructure does not work beyond business hours — and does not need online support.

At TIER II, the annual availability is about 99.749%. Thus, there can be up to 22 hours of downtime each year.


In addition to fulfilling all the requirements of the levels above, TIER III is totally redundant.

It’s the ideal choice for modern companies that operate at all times and need constant support for their technological tools and automation solutions. Tolerated downtime is only 1.6 hours each year, because its availability must be at 99.98%.

One detail is that TIER III infrastructures cannot be located beyond a 1-mile radius from airports.


TIER IV is the last classification (which also meets all previous requirements). Its main characteristic is robustness: it continues to operate even if its system or one of its elements fail.

In addition to redundancy, there must be several electrical systems and subsystems operating simultaneously. It’s fitting for multinational companies, with operations that require uninterrupted care.

An example of organizations that would be interested in this Tier are the large credit card operators.

Its availability must be 99.999%, and tolerated downtime is only 26 minutes each year.

Ascenty Data Centers: Tier III classification at your disposal

Throughout Latin America, not only in Brazil, companies are increasingly looking for reliable providers. In order to make sure that your data center investment will pay off, you need robust technology to ensure availability and quality.

That is why Ascenty has worked hard to earn its TIER III classification. That’s right: the infrastructure of Latin America’s largest data center company also meets the leading quality requirements.

According to the Uptime Institute, Ascenty offers 99.982% availability at its data centers.

However, internally, the company guarantees 100% for infrastructure. There are multiple and independent distribution paths to the IT equipment.

In addition, the IT equipment is dual-fed, compatible with the site topology. The construction quality of Ascenty’s data centers is impressive, as the company aims to stand out from its competitors.

The goal is to offer cutting-edge solutions, ensuring high levels of connectivity and interconnection. As a result, your business will grow supported by high-quality resources, tools and infrastructure.

Why not find out how Ascenty can help your company to establish the best data and connection infrastructure? Talk to one of our experts!