Difference between Hard real time systems and Soft real time systems

Real time operating systems are categorized into:

Hard real-time systems complete the critical tasks within the definite interval of constraints. If the critical task is not completed within the time constraint, then the hard real time system fails.
Thus, a hard real time system has to complete all the processes within a definite deadline and a single miss leads to critical failure.
The example of hard real time system is a flight controller system in which any miss in deadline leads to a crash or an unstable aircraft.

Soft real-time systems are less restrictive in nature and are not affected by the lapse of time interval and do not cause any critical failure.
Soft real time system are used in the area of multimedia, virtual reality. The example of soft real time system is nuclear power stations and airbags.
Examples of soft real time operating system are Harmony (Developed by National Research Council of Canada), Maruti (University of Maryland), OS9 (Microware System Corporations), RTEMS (Real Stone Military Arsenal)

S. No.	Soft real-time systems	Hard real-time systems
1.	Soft real time systems require good response but allow some fudge in deadlines.	Hard real time systems have absolute deadlines. It requires having good response all the time. Failing to respond properly is fairly unacceptable.
2.	Real time operating system for cordless bar code reader needs goods response time but some limited delay due to some problem is acceptable.	Example of hard real time system is system used for nuclear reactor. These system don’t effort delay in response to any problem for even 1% of time.
3.	It supports advanced operating system features. So it has expanded uses than hard real time operating system.	Most secondary storage and advanced operating system features are missing as they enhance uncertainty about amount of time an operating will take. For instance virtual memory is not used in such systems.