CBE / MET 433 25 April 2012

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Statistical Process Control

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PS Exercise: Control Charts

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SPC Quick Summary

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Control Chart ExamplesData from 99 samples of the silicon content drawn from a blast furnace. Data organized into 33 subgroups of size 3.

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Control Chart Examples

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Control Chart Examples

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Control Chart ExamplesData from 99 samples of the silicon content drawn from a blast furnace. Upon further inspection it was discovered that each sample was the first tap from each shift…thus 3 silicon values for each day.

The sample subgrouping was supposed to represent each day, however it was recorded in columns not rows, thus 144, 150 and 180 was the 1st day’s samples. The data was reorganized and rerun.

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Control Chart Examples

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Control Chart Examples

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Control Chart ExamplesSubgroups of 5 samples from each shift.

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Control Chart ExamplesSubgroups of 5 samples from each shift.

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Control Chart ExamplesExtruded vinyl sheet to be used for car dashboard. Thickness controlled by automatic system.

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Questions?

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Questions?