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X-bar chart. In industrial statistics, the X-bar chart is a type of Shewhart control chart that is used to monitor the arithmetic means of successive samples of constant size, n. This type of control chart is used for characteristics that can be measured on a continuous scale, such as weight, temperature, thickness etc. For example, one might ...
The sample size is relatively small (say, n ≤ 10— ¯ and s charts are typically used for larger sample sizes) The sample size is constant; Humans must perform the calculations for the chart; As with the ¯ and s and individuals control charts, the ¯ chart is only valid if the within-sample variability is constant. [4]
The sample size is relatively large (say, n > 10— ¯ and R charts are typically used for smaller sample sizes) The sample size is variable; Computers can be used to ease the burden of calculation; The "chart" actually consists of a pair of charts: One to monitor the process standard deviation and another to monitor the process mean, as is ...
File:Xbar chart for a paired xbar and s chart.svg. Size of this PNG preview of this SVG file: 600 × 599 pixels. Other resolutions: 240 × 240 pixels | 481 × 480 pixels | 769 × 768 pixels | 1,026 × 1,024 pixels | 2,051 × 2,048 pixels | 630 × 629 pixels. This is a file from the Wikimedia Commons. Information from its description page there ...
File:Xbar chart for a paired xbar and R chart.svg. Size of this PNG preview of this SVG file: 600 × 599 pixels. Other resolutions: 240 × 240 pixels | 481 × 480 pixels | 769 × 768 pixels | 1,026 × 1,024 pixels | 2,051 × 2,048 pixels | 630 × 629 pixels. This is a file from the Wikimedia Commons. Information from its description page there ...
The Western Electric rules are decision rules in statistical process control for detecting out-of-control or non-random conditions on control charts. [1] Locations of the observations relative to the control chart control limits (typically at ±3 standard deviations) and centerline indicate whether the process in question should be investigated for assignable causes.
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Shewhart individuals control chart. In statistical quality control, the individual/moving-range chart is a type of control chart used to monitor variables data from a business or industrial process for which it is impractical to use rational subgroups. [1] The chart is necessary in the following situations: [2]: 231.