Which of the following best practices gives administrators a set period to perform changes to an operational system to ensure availability and minimize business impacts?

Scheduled downtime is a best practice that allocates a specific, pre-determined period for administrators to implement changes, updates, or maintenance on an operational system. This approach is crucial for ensuring system availability and minimizing disruption to business operations by performing work during off-peak hours or when impact is lowest. Impact analysis is the process of evaluating the potential effects of a change but doesn't provide the timeframe for execution. A backout plan is a contingency for reverting changes if issues arise, not the period for performing them. Change management boards (or committees) are responsible for approving and overseeing changes, but they don't define the specific window for implementation.