关键词: 事件间隔时间, 中位数控制图, 参数估计, 平均运行链长, Bootstrap方法

Abstract: To monitoring the time between events following exponential distribution of the high quality process,firstly,the design procedure of the median control chart was proposed to monitor time between events following exponential distribution for both the known and unknown parameter case.Then,the effects of parameter estimation on the chart performance were evaluated in terms of conditional false alarm rate,the AARL and the SDARL.Thirdly,the bootstrap method was proposed to adjust the control limits for the small sample problem.Results showed that the adjusted control limits could efficiently reduce the effects of parameter estimation on the chart performance.Finally,an illustrative example was given to verify the effectiveness of the proposed control chart.

Key words: time between events, median control chart, parameter estimation, average run length, Bootstrap method