Moving Average Chart Control Limits

The upper & lower control limits for the Moving Average chart.

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where n is the subgroup size, w is the moving (cell) size, σx is the process sigma based on the Moving Range chart or the Moving Sigma chart, and X-doublebar is the overall average:

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m is the total number of subgroups

A Moving Range or Moving Sigma chart is used to monitor process variation.

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Learn more about the SPC principles and tools for process improvement in Statistical Process Control Demystified (2011, McGraw-Hill) by Paul Keller, in his online SPC Concepts short course (only $39), or his online SPC certification course ($350) or online Green Belt certification course ($499).