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Owning Palette: Statistical Process Control VIs

Installed With: Statistical Process Control Toolkit. The objects available on this palette vary according to the packages you have installed.

Use the Process Statistics VIs to estimate process distributions and capabilities, calculate and plot histograms, and plot and fit normal probability distribution functions to histograms.

The Process Statistics VIs perform the following operations:

• Compute process mean and sigma
• Compute process capability ratios and reject rates
• Create and graph histograms
• Plot normal probability distribution functions against histograms and process specification limit

Palette Object	Description
Compute Process Capability	Given the specification limits and the process mean and process sigma, computes the process capability ratios Cp, Cpk, and Cpkm as well as the estimated process fraction non-conforming in parts per million (ppm). Notice that the fraction non-conforming is valid only if the process is normally distributed. Computes one-sided upper and one-sided lower in addition to two-sided process capability ratios and fraction non-conforming.
Fit Nrml PDF to Histogram	Given the bin centers from a histogram (axis values output from the General Histogram VI), the estimated sigma of the observations for the histogram, and the total number of observations in the histogram, calculates the height for a normal probability distribution function (PDF) that fits the histogram.
General Histogram	Finds the discrete histogram of the input sequence X based on the given bin specifications.
Process Mean & Sigma	Computes process mean and sigma and upper and lower natural process limits from process samples. You can estimate the process sigma in several ways. If the sample size is greater than one, you can use either sample standard deviation s or range R to estimate the process sigma. You select s or R by the type input. If the sample size is one, the VI automatically uses the moving range to estimate the process sigma.
Sample Statistics	Computes statistics on the input array sample X.

Subpalette	Description
Process Statistics Graphing VIs	Use the Process Statistics Graphing VIs to plot graph for process statistics.

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