Effective data centre operation requires a balanced investment in both the facility and the housed equipment. The higher the availability needs of a data centre, the higher the capital and operational costs of building and managing it. virtualisation technologies to replace or consolidate multiple data centre equipment, such as servers. Virtualisation helps to lower capital and operational expenses.
The Tier classifications were created to consistently describe the site-level infrastructure required to sustain data centre operations, not the characteristics of individual systems or subsystems. Data centres are dependent upon the successful and integrated operation of at least 16 separate site infrastructure subsystems. Every subsystem and system must be consistently deployed with the same uptime objective to satisfy the distinctive Tier requirements. The most critical decision making perspective owners and designers must consider, when making an inevitable trade-off, is what effect does the decision have on the life cycle integrated the operation of the data centre.