Availability Definition


Availability is a performance criterion for repairable systems that accounts for both the reliability and maintainability aspects of a system. It is defined as the probability that the system is operating properly when it is required for use. That is, availability is the probability that a system is not failed or undergoing a repair action when it needs to be used. The numerical value of availability is expressed as a probability from 0 to 1. Availability calculations take into accounts both the failures and repairs of the system. For example, if a lamp has 99.9% availability, there will be one time out of a thousand that someone needs to use the lamp but it is non-operational because the switch is broken, or it is waiting for the replacement of a light bulb etc.   


Post a Comment