Process Capability Options in SPC for Excel

Easily see if your process is meeting customer specifications with SPC for Excel’s process capability techniques for normally and non-normally distributed data:

Capability level

NORMAL PROCESS CAPABILITY SNAPSHOT

Consists of Cpk chart, control chart (either X-R, X-s or X-mR), normal probability plot and select statistics

Cpk chart: contains many of the options listed below

Select Out of Control Tests for control chart

Includes Anderson-Darling statistic and p value for normal probability plot

Select statistics included at bottom of page

NON-NORMAL PROCESS CAPABILITY SNAPSHOT

Consists of Ppk chart, control chart (either X-R, X-s or X-mR), P-P plot to test the fit of the distribution and statistics

Ppk chart: contains many of the options listed below

Select out of control tests for control chart

Includes Anderson-Darling statistic and p value for the P-P plot

Select statistics included at bottom of page

NORMAL PROCESS CAPABILITY (CPK/PPK)

Histogram

Lower specification limit, nominal (if entered), upper specification limit (only one specification is required as the software handles one-sided specifications)

Normal curve based on estimated sigma and/or calculated standard deviation

+/- 3 sigma limits based on estimated sigma and/or calculated standard deviation

Plot average

Shade/unshade histogram option

Confidence limits for Cpk and Ppk

For subgroups, base estimate of sigma on average range, average standard deviation or pooled variance

Output Statistics Options:

Within Process Capability (based on estimated sigma)

Cp, Cpk, Cpu, Cpl

Estimated Sigma (from range or standard deviation chart)

PPM > USL

PPM < LSL

Total PPM out of specification

Sigma level

Subgroup Size

Overall Process Capability (based on calculated standard deviation)

Pp, Ppk, Ppu, Ppl

Calculated Sigma

PPM > USL

PPM < LSL

Total PPM out of specification

Sigma level

General Statistics

Average

Count

Number out of specification

Minimum

Maximum

Add target (to calculate Cpm)

Option to remove outliers

Option to use historical average and standard deviation in the calculations

Option to transform the data with Box-Cox or Johnson transformations

Add dates of data collection

Change the number of classes, the class width or the starting point on the histogram

Easily update with new data

Process capability table to summarize all process capability charts in a workbook

NON-NORMAL PROCESS CAPABILITY (PPK)

Histogram

Lower specification limit, nominal (if entered), upper specification limit (only one specification is required as the software handles one-sided specifications)

Select one of 13 distributions for the analysis:

Exponential

Exponential - Two Parameter

Gamma

Gamma - Three Parameter

Largest Extreme Value

Logistic

LogLogistic

LogLogistic - Three Parameter

LogNormal

LogNormal - Three Parameter

Normal

Smallest Extreme Value

Weibull

Weibull - Three Parameter

Option to enter the parameters for the distribution or have SPC for Excel find the best-fit parameters

Option to plot average

Option to shade the histogram

Add dates of data collection

Add titles and axis labels

Add target to calculate Cpm

Change the number of classes, the class width or the starting point on the histogram

Easily update with new data

Process capability table to summarize all process capability charts in a workbook