鉴于小批量生产过程生产周期短、产品数目较少,实施统计过程控制中没有足够的样本数据来构造控制图,针对两阶段串联可修系统,研究统计过程控制与维修策略整合的问题。首先,根据t统计量的特性给出EWMAt-残差t(EWMAtX-te)联合控制图,并分析EWMAtX-te控制图的一些统计属性,应用EWMAtX-te控制图监控系统的质量状态,根据质量状态采取相应的维修策略;其次,采用Markov链构建了统计过程控制与视情维修整合的数学模型;然后,针对具体实例,将构建的模型与不采用统计过程控制监控策略的情形和采用经验法则选取控制图的设计参数模型进行比较分析,结果表明构建的模型在节约成本方面具有明显的优势;最后,运用分式析因设计对过程参数、时间参数和成本参数进行了敏感性分析,验证了所提方法的有效性。
Owing to the limited time horizon and finite population items of short-run production process, there were not enough samples data to build the control chart in Statistical Process Control (SPC) process. Aiming at the two- stage series repairable system, the integration problem of maintenance strategy and SPC process oriented to short- run production was proposed. According to the feature of t statistic, EWMAtx-tc. joint control chart was built, and the statistical properties of joint control chart was analyzed. The quality state of system was monitored by joint con- trol chart monitors, and the corresponding maintenance strategy was adopted according to the quality state. The in- tegrated mathematical model of SPC and Condition Based Maintenance (CBM) was constructed by using Markovchain. A numerical example was given to illustrate the application of the proposed integrated model, and the results showed that the proposed model had advantage on cost saving by comparing with the different situations. A sensitiv- ity analysis for process parameter, time parameters and cost parameters was conducted by using fractional factorial design, and the effectiveness of proposed method was proved.