Abstract: System reliability is one important factor for the evaluation or confirmation of the architecture of a flight control computer system (FCCS). System reliability modeling techniques (SRMTs) are crucial to evaluate system reliability quantificationally. Commonly used SRMTs include the reliability block diagram (RBD), fault tree analysis (FTA), Markov stochastic process and Petri net, each of which has its advantages and disadvantages. This article proposes a hierarchical combination reliability modeling (HCRM) method for multiple redundancy FCCS by synthesizing both static and dynamic SRMT. By this method, the system reliability model for dissimilar redundancy FCCS of Boeing 777 is described. Compared with the traditional approaches, the HCRM method can combine state-based reliability modeling techniques with non-state-based ones, realize hierarchical modeling and solve a process based on static and dynamic characteristics of the system. Thus, we can disassemble the complexity of a system and reduce the difficulty of solution, and make the system reliability model more consistent with real complex systems.

Key words: reliability, modeling, flight control computer system, redundancy, hierarchy, combination