Abstract： In manufacturing systems, the complex parts like astronautical valve are often processed through several correlated stages. It is absolutely of great importance to evaluate and analyze the quality of such correlated multistage systems. This paper, based on the Markov chain method and incorporating iteration, presented an analytical model to evaluate the quality of the correlated multistage system. The model took machine states as well as the quality of the incoming parts into consideration. It emphasized the quality propagation between adjacent stages, revealed the quality changes after each stage and proposed to improve the quality of the final product from the aspect of the parameters of the processing machine. The effectiveness of this model was validated by a case of multistage manufacturing system of astronauticalvalve used in a domestic rocket manufacturing company.
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