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Statistical Process Control (SPC) capabilities in the FactoryLogix Analytics client application are available through an optional licensed module. Contact Aegis if you're interested in adding these SPC capabilities to your FactoryLogix system. |
SPC control chart types
np, p, c, and µ type control charts are referred to as attribute control charts. These control charts are used when you have "count" type data.
There are two basic types of attributes data—the type of data you have determines the type of control chart to use.
- Yes/No data
- Counting data
To summarize SPC attribute control chart types:
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Defective Units per Batch (p chart)
The p control chart is used to monitor the proportion of defective units in a sample, where the sample proportion of defective units is defined as the ratio of the number of defective units to the sample size, n.
The purpose of a p chart is to evaluate process stability when counting the fraction defective. A p chart is used when the sample size varies, for example: the total number of circuit boards or bills delivered varies from one sampling period to the next. More information: p chart (Wikipedia.org)
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