We’ve all heard of the basic statistical terms: mean, median, and mode, but when it comes to Statistical Process Control things get a bit more complicated. This “Key Term Tuesday” we’re focusing on SPC.

Statistical Process Control or SPC is a collection of tools that analyze processes and takes the appropriate actions to achieve and maintain statistical control while improving process capability.

p, c, np, and u charts: control charts that analyze attribute data usually gathered in the form of nonconforming units or of nonconformities.

CUSUM: a control chart approach designed to detect small process shifts in the process average or variability by looking at the current and recent past process data. CUSUM stands for “cumulative sum” of deviations from the target and puts equal weight on the current and recent past data.

Moving range: A measure of process spread. The difference between the highest and lowest value among two or more successive samples.

Poisson distribution: A discrete probability distribution for attributes data that applies to nonconformities and underlies the c and u control charts.

Attribute data: qualitative data that can be counted for recording and analysis.

Looking for more on SPC or how it fits into your Continuous Quality Improvement plan? Download our CQI-25 SPC Quick Start Guide.

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