On-Line SQC/SPC Charting

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An automated SQC/SPC function is available within the WinLIMS web client that is used to help your company better control the manufacturing process. The module serves as an interactive tool that can be used by the laboratory to immediately identify processes that are out of control using Western Electric Alarm Actions.


Statistics are automatically calculated for each parameter upon results verification (validation) and a statistical conformance/violation status is applied so you can immediately tell if there is a production or laboratory problem that needs to be investigated. SQC graphs can be instantaneously presented that shows historical results and control limits to immediately identify problems. In addition to the graph itself, the mean, 1 sigma, 2 sigma, 3 sigma, Cp and CpK values are presented along with the chart. A distribution chart is also provided to ensure that you have a complete picture of the production process.


Western Electric Alarm Actions

The following is a description and graphical depiction of the Western Electric statistical violation alarm actions for your review. You may use one or more of these (and may know them by different names) and WinLIMS.NET lets you choose which to apply.


1 point more than 3 sigma from center line Western-Electric-Rule-1.JPG
9 points in a row on the same side of center line Western-Electric-Rule-2.JPG
6 points in a row, all increasing or all decreasing Western-Electric-Rule-3.JPG
14 points in a row, alternating up and down Western-Electric-Rule-4.JPG
2 of 3 points more than 2 sigma from center line Western-Electric-Rule-5.JPG
4 out of 5 points more than 1 sigma from center line Western-Electric-Rule-6.JPG
15 points in a row within 1 sigma of center line Western-Electric-Rule-7.JPG
8 points in a row more than 1 sigma from center line Western-Electric-Rule-8.JPG


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