High-performance embedded applications must often manage time-critical responses Examples include manufacturing process controls, high-speed data acquisition devices, telecommunication switching equipment, medical monitoring equipment and so on Validating such an application means examining not only its computational accuracy, but also the timeliness of its results The application must deliver its responses within specified time parameters in real-time. A real-time system is one in which the correctness of the computations not only depends on the logical correctness of the computation, but also on the time at which the result is produced If the timing constraints of the system are not met, system failure is said to be have occurred. Generally said, a RTOS must have the following

• It must be multi-tasking and preemptive
• It must support task priority
• A system of priority inheritance must exist
• It must support predictable task synchronization mechanisms