Abstract

In this article, we propose an ATTRIVAR chart to control the process mean. With the ATTRIVAR chart, the sampling is performed in two stages, collecting attribute and variable sample data from the same sample (attribute plus variable data – ATTRIVAR). That is, if the first m items of the sample fail to pass the go gauge test, or they pass the no-go gauge test, the sampling moves on to stage two, where the quality characteristic X of the first m and the remaining n-m items of the sample is measured. Otherwise, the sampling is interrupted and the process is declared to be in control. The number of tested items, if one, or two, or as many as m, is only known after the completion of the first stage. At the second stage, the $\overline{X}$ value is computed and used to decide the state of the process. It is worthwhile to stress that the go/no-go gauge test truncates the X distribution and, because of that, the mathematical development to obtain the $\overline{X}$ distribution is not trivial. The ATTRIVAR chart signals faster than the Double Sampling $\overline{X}$ chart and, more important than that, it is simpler to use because the go/no-go gauge test reduces the frequency with which the quality characteristic X of the sample items is measured. The ATTRIVAR chart is also faster and simpler than the mixed chart. With the mixed chart, the sampling is also performed in two stages; the difference is that all items of the sample are always submitted to the go/no-go gauge test before deciding to go to stage two, where the $\overline{X}$ value is computed.

摘要

在本文中，我们提出了一个 ATTRIVAR 图来控制过程均值。使用 ATTRIVAR 图表，抽样分两个阶段执行，从同一样本中收集属性和变量样本数据（属性加变量数据 - ATTRIVAR）。也就是说，如果样品的前m个项目未能通过 go gauge 测试，或者它们通过 no-go gauge 测试，则采样进入第二阶段，在此阶段前m和剩余nm的质量特性X测量样品的项目。否则，采样被中断，过程被宣布为受控。测试项目的数量，如果是一个，或两个，或者多达m，只有在第一阶段完成后才知道。在第二阶段，$\overline{X}$value 被计算并用于决定进程的状态。值得强调的是，通过/不通过规范测试会截断X分布，正因为如此，获得$\overline{X}$分配不是微不足道的。ATTRIVAR 图表比双采样更快地发出信号$\overline{X}$更重要的是，它更易于使用，因为通过/不通过量规测试降低了测量样本项目质量特性X的频率。ATTRIVAR 图表也比混合图表更快、更简单。使用混合图，采样也分两个阶段进行；不同之处在于，在决定进入第二阶段之前，样本的所有项目总是提交给通过/不通过量规测试，其中$\overline{X}$计算值。