Comment by waisbrot

An easy example: you need 5 minutes of planned downtime (which is entirely within SLAs) to execute a major upgrade, but the system is also used by Sales for demos to major new clients. "We're going to take 5 minutes of downtime on Wednesday evening for an upgrade. Contact me ASAP if this is a problem for you." If you don't hear from the team, then it's OK to go.