Research On The Relationship Between The Reliability Of The Complex System And Its Complexity

With the development of social economy, science and technology, many systems which are closely bound up to people's life and work become more and more complex and heir reliability increase. As the complexity of the system increases, the influence between each other, the coupling and connections inside the systems become stronger, which increase the difficulty of the coordination between them. The probability of failure and unpredictability of whole system raise, as the reliability reduces.In order to explore the relationship between reliability and complexity of complex system, and to make an objective reliability evaluation and measurement of airlines with different complexity, we choose airlines as our research object of complex system. We make an analysis based on its complexity and reliability, then we determine the factors of complexity which influence the reliability and make a division of system by using methods of system engineering. We apply reliability theory and methods to explore the composition, structure, function and coupling of system, and establish respectively the personal subsystem, fleet subsystem and management subsystem. Then using the methods of system reliability calculation, we make improvement and modification by taking account of effects by the system complexity factors. At last we obtain reliability calculation model of the system and subsystem which is based on the complexity, and give respectively the reliability expression of subsystems which taking account of the complexity factors.Finally, according to the process of accident or unsafe events, we obtain the reliability of whole airlines which is coupling effected by human, machine, environment and management.That is a calculation method to measure reliability of different airlines with different complexity.