If the drive fails, RST will actively demote it and detect issues in real time, indicated by a Yellow Exclamation mark in the software and system-time area popups. The system will survive a drive failure or having a single drive unplugged while running... but your board must support HOT PLUGGING, in the case of physically unplugging. If a bad drive is found, shut the system down, replace the failed drive with a new, blank drive and start the CPU. The array rebuild process is done, again, from the RST software in Windows.
I have never had success of hot plugging a system of it's bad drive, swapping in the new, and then performing a build in the same OS session... a reboot seems to be required on the systems I worked on. So, if it were like a mission-critical server and you wanted Zero-downtime for drive swaps... RST isn't the right choice.