The CCB makes a few decisions for you based on the variable selected. For example, if there is no X variable, a cchart is originally created because there is no way to estimate the binomial distributions. Upon adding an X variable (or lot size), the platform switches to a npchart if the count per subgroup is less than the subgroup sample size. Once the basic chart is created, you can use the menus and other options to change the type, the statistic, and the format of the chart.
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pcharts display the proportion of nonconforming (defective) items in subgroup samples, which can vary in size. Because each subgroup for a pchart consists of Ni items, and an item is judged as either conforming or nonconforming, the maximum number of nonconforming items in a subgroup is Ni.

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npcharts display the number of nonconforming (defective) items in subgroup samples. Because each subgroup for a npchart consists of Ni items, and an item is judged as either conforming or nonconforming, the maximum number of nonconforming items in subgroup i is Ni.
