Control limit: Difference between revisions
wikademia>Toll booth No edit summary |
wikademia>Jayen466 make clear that it is s.d. of the plotted statistics, not the s.d. of the raw values |
||
| Line 1: | Line 1: | ||
'''Control limits''' are horizontal lines drawn on an [[statistical process control|statistical process]] [[control chart]], usually at a distance of ±3 [[standard deviation]]s | '''Control limits''' are horizontal lines drawn on an [[statistical process control|statistical process]] [[control chart]], usually at a distance of ±3 [[standard deviation]]s of the plotted [[statistic]] from the statistic's [[mean]]. | ||
For [[normal distribution|normally distributed]] statistics, the area bracketed by the control limits will on average contain 99.73% of all the plot points on the chart, as long as the process is and remains in statistical control. | For [[normal distribution|normally distributed]] statistics, the area bracketed by the control limits will on average contain 99.73% of all the plot points on the chart, as long as the process is and remains in statistical control. | ||
Revision as of 20:10, 23 April 2008
Control limits are horizontal lines drawn on an statistical process control chart, usually at a distance of ±3 standard deviations of the plotted statistic from the statistic's mean.
For normally distributed statistics, the area bracketed by the control limits will on average contain 99.73% of all the plot points on the chart, as long as the process is and remains in statistical control.
Control limits should not be confused with tolerance limits, which are completely independent of the distribution of the plotted sample statistic.
 | This statistics-related article is a stub. You can help Wikipedia by expanding it. |
 | This industry-related article is a stub. You can help Wikipedia by expanding it. |