A new method for reliability allocation of avionics connected via an airborne network

Avionics are connected via an airborne network, and the realization of their functions depends on successful data transmission through the network. Once the system reliability goal has been defined, reliability allocation must be performed to the subsystems and components. However, the widely used reliability allocation methods are not capable of dealing with complex connections between avionic subsystems. In this paper, an improved Advisory Group on the Reliability of Electronic Equipment (AGREE) allocation method is proposed for multi-mission networked avionics. In the proposed procedure, both the complexity and the importance of components are explicitly considered. Analytic algorithms and Monte Carlo simulation are applied to calculate the reliability of such a complex network structure. To determine the reliability allocation values, a heuristic algorithm is proposed, and an allocation adjustment procedure is provided to avoid inconsistent allocations caused by the same category of components involved in multiple missions of avionics. Our numerical study on A380 avionics, whose data are transmitted through Avionics Full Duplex Switched Ethernet (AFDX), shows that the proposed method is practical and quite efficient in handling such complex reliability allocation problems.