Autonomous successive construction technology without stopping system operation for real-time system

Recent large real time systems have required system expandability with heterogeneous functions and operations. A high assurance system is very important for such systems. In order to realize a high assurance system, we research autonomous successive construction technology without stopping system operation for real time systems. This technology is also called step-by-step system construction. In this paper we propose functional reliability and online functional availability as the best index to indicate assurance performance for system construction. According to this new index, the best solution for system construction is a construction pattern to put large subsystems online at first, and to put small subsystems online gradually. Moreover we propose the importance rating as an index to determine online input sequence.