The real-time operating system is designed to support executions of programs within strict time limits. The real-time system requires the correct results within the specified time period. The correctness of the program's result is totally dependent on the completion of the job within the specified period. Many real-time systems are embedded in specialized devices, such as microwave ovens, washing machines, digital cameras, cellular telephones. For example, human brain works on the principle of real time operating system. Real-time operating systems are used in medical imaging system, airline reservation system, telecommunication system, military weapons control systems, and many other laboratory experiments etc.