Systematic discipline for designing, developing, testing, deploying, and maintaining software.

Practices ensuring critical operations continue during disruptions.

Processes for restoring systems after major failures.

Average time required to repair a failed system.

Average operating time before a failure occurs.

Average time required to restore service after failure.

Average operating time between system failures.

Allowed amount of service unreliability under an SLO.

Formal agreement defining expected service performance.

Target value for a service-level indicator.