面向质量目标的Q控制图设计

针对大批量生产开始阶段的过程监控,提出了一种基于预定质量目标的Q控制图监控方法.其基本思路是利用面向质量目标的统计公差技术与Q控制图相结合应用,以实现大批量过程开始阶段均值和方差未知时面向质量目标的过程监控.基于质量目标建立统计公差(CP*,k*),并将该统计公差转化为基于给定置信概率的对CP和k的估计值的判定条件.通过案例分析,面向质量目标的Q控制图能够在过程保持受控状态的前提下以一定置信概率保证质量目标.

Design of Q control charts for assuring predetermined process quality

Aiming at monitoring processes in the early phases of long-run mass-manufacturing,a new quality-oriented Q control chart was presented based on the predetermined quality target.In order to assure the designated process quality in short production runs and in the early phases of long-run designated process quality,the main approach was to monitor processes combining the quality-oriented statistical tolerance technique with a Q control chart.The statistical tolerance(C*P,k*) was established based on the predetermined quality target,and the statistical tolerance(C*P,k*) was turned into the judgment condition of the estimate of CP and k based on the given confidence probability.The case study shows that the quality-oriented Q control chart can assure process quality with preset confidence probability under the condition that the process is in the controlled state.