Realtime doesn't mean error free. A realtime OS might provide some form of a watchdog feature where it can detect when a program fails to meet its deadline. Thi

Realtime doesn't mean error free. A realtime OS might provide some form of a watchdog feature where it can detect when a program fails to meet its deadline. Think of it like a segfault in a traditional system. If everyone did their job correctly, it would never come up, but people make mistakes and it is better to detect them and fail in a controlled manner than it is not notice and fail in unpredictable ways.