Abstract: Network Analytical Method is a method for evaluating the reliability of a complex system. The network is defined as a graph which only contains simple nodes and arcs（no duplicative arcs）. In this paper, however, the method is extended to redundant systems which contain vote nodes and arcs, inclusive of duplicative arcs. In addition, coverage is taken into account in the model.The RSCA-III Algorithm can predict reliability for any network with duplicative arcs. After finding all minimal paths, the RSCA- I Algorithm uses cube for discribing the states and paths of system and then applies Sharp （#） operation between cube sets for obtaining the reliability of the system.Finally, a numerical example is given for a fly-by-wire flight control system on four-redundancy. The variation of reliability with second fault coverage is determined. The results verify the applicability of the model and the algorithm for engineering practice.