Great framing of perspective. We've been leveraging the 5-9's definition from the ITU for decades, but most segments of technology bring it into their own backyard in slightly different shapes. Dialtone was, and is, the ITU definition of 5-9's (and even that has exceptions).
Some segments measure on the ability to make a request (dial-tone), some on request completion (concluding that conversation with your girlfriend, uninterrupted), yet others focus on the ability to complete the conversation within a set amount of time. There are many others, but each and every one of them have implied assumptions around the role of the service and the ecosystem they reside in (maturity, complexity, criticality, and so on).
Great framing of perspective. We've been leveraging the 5-9's definition from the ITU for decades, but most segments of technology bring it into their own backyard in slightly different shapes. Dialtone was, and is, the ITU definition of 5-9's (and even that has exceptions).
Some segments measure on the ability to make a request (dial-tone), some on request completion (concluding that conversation with your girlfriend, uninterrupted), yet others focus on the ability to complete the conversation within a set amount of time. There are many others, but each and every one of them have implied assumptions around the role of the service and the ecosystem they reside in (maturity, complexity, criticality, and so on).