According to a survey carried out by the Uptime Institute, data center outages are on an upward trend and are mainly caused by failures within electrical systems. An unreliable power grid presents a unique challenge to data center operators. To maintain uninterrupted power supply to the IT load in a data center during planned or unplanned utility outages, an open transition between the utility and generator supply will typically form part of the sequence of operations in the event of utility power loss. During the open transition, a double-conversion UPS will change modes of operation to ensure continuity of supply; the utility breaker will open, and the generator breaker will only close once the defined parameters are met, such as when the generator power supply is stable. This research study evaluates how availability modelling techniques can be used as tools to help predict and improve data center availability. Each modelling technique will be measured against a set of criteria to establish their subsequent capabilities and limitations. The concept of availability modelling is used across multiple industries, including aviation. To achieve this, the research evaluates five widely used modelling techniques.

Keywords

Markov, Reliability block diagram, Fault Tree Analysis, Stochastic Petri Nets and Failure Mode Effect and Criticality Analysis