What is the term used for an interval when a system is unavailable to users?

The correct term for an interval when a system is unavailable to users is "downtime." Downtime specifically refers to periods when a system, application, or service is not operational, preventing users from accessing it. This can occur due to a variety of reasons, including scheduled maintenance, unexpected technical failures, or system upgrades that render the service temporarily unavailable.

In the context of healthcare, managing downtime is crucial, as it can directly impact patient care, data access, and overall service delivery. Being aware of downtime helps healthcare providers communicate effectively with users, ensuring that they understand the situation and can plan accordingly.

The other options refer to related but different concepts. System maintenance typically pertains to planned work done to keep the system functioning optimally, which is not necessarily the same as downtime, though it can lead to it. Technical failure denotes an unexpected problem causing system inaccessibility but does not capture the broader context of scheduled and unscheduled unavailability. An outage period can describe a time when a service is down, but "downtime" is the more widely accepted term used to encompass all instances of unavailability.