Control limits, also known as natural process limits, are horizontal lines drawn on a statistical process control chart, usually at a distance of ±3 standard deviations of the plotted statistic from the statistic's mean.
Control limits should not be confused with tolerance limits or specifications, which are completely independent of the distribution of the plotted sample statistic. Control limits describe what a process is capable of producing (sometimes referred to as the “voice of the process”), while tolerances and specifications describe how the product should perform to meet the customer's expectations (referred to as the “voice of the customer”).
Read more about Control Limits: Use
Famous quotes containing the words control and/or limits:
“I don’t think I was constructed to be monogamous. I don’t think it’s the nature of any man to be monogamous.... Men are propelled by genetically ordained impulses over which they have no control to distribute their seed into as many females as possible.”
—Marlon Brando (b. 1924)
“... there are no limits to which powers of privilege will not go to keep the workers in slavery.”
—Mother Jones (1830–1930)