中文摘要：

针对输出质量特性服从正态分布的随机偏移单部件可修系统，研究了可变样本容量和控制线（Variable Sampling Size and Control Limits，VSSCL）均值控制图和预防维修策略联合经济设计问题。首先，构建了VSSCL均值控制图和预防维修策略联合经济设计的集成框架，揭示控制图和预防维修策略运行的耦合机制；然后，基于VSSCL均值控制图和系统状态特征参数，针对给出的集成框架确定了可能形成系统更新的四个维修事件的发生概率，并进一步利用更新过程理论和全概率公式，建立了VSSCL均值控制图和预防维修策略联合经济设计的平均单位时间成本最小决策模型；同时，针对具体实例，将构建的联合设计决策模型和独立设计决策模型进行比较分析，结果表明联合设计决策模型具有明显的经济优势；最后，利用回归正交试验设计方法对模型参数的灵敏度进行了分析。

英文摘要：

For one unit repairable system having a normal distribution of products quality failure, considering random shift, a joint economic design approach to Variable Sampling Size and Control Limits（VSSCL） X-bar control chart and preventive maintenance policies is discussed. Firstly, an integrated frame structure on VSSCL X-bar control chart and preventive maintenance policies is developed to reveal the running coupling mechanism between control chart and preventive maintenance policies. Secondly, for the integrated frame structure, probabilities models of four repair events which can lead to system renew are given based on VSSCL Xbar control chart and the system condition characteristic parameters. Then, a mathematical decision model on joint economic design for dynamic SPC and preventive maintenance policies is presented to find the minimization average cost per unit time according to renew theory and the law of total probability decomposition, and a comparison shows that the proposed joint economic design model has a lower average cost per unit time than previous independent economic design model. Finally, a sensitivity analysis for model parameters was conducted by using orthogonal regression design.