cl05_Quality_Management_II

Length size weight height velocity etc monitor the

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Unformatted text preview: ight, height, velocity, etc. length size weight height velocity etc – Monitor the mean values Attribute control chart Attribute control chart (p-chart) – For product characteristics evaluated with a discrete choice Example: good/bad, yes/no, etc. – Monitor the percent defectives 15 Stephen Shum Spring 2009 Example 1: LCD Display Example 1: LCD Display Test the quality and Test the quality and performance performance of LCD displays before shipping displays before shipping Test for – Contrast – Color scales – Dead pixels – … and more 16 Stephen Shum Spring 2009 Calculating Control Limits Calculating Control Limits Period 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 n 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 defects 18 15 18 6 20 16 16 19 20 16 10 14 21 13 13 13 17 17 21 18 16 14 33 46 10 12 13 18 19 14 p 0.060 0. 050 0.060 0.020 0.067 0.053 0.053 0. 063 0.067 0.053 0.033 0.047 0.070 0.043 0.043 0.043 0.057 0.057 0. 070 0.060 0.053 0.047 0.110 0.153 0. 033 0.040 0.043 0.060 0.063 0.047 • n = sample size • p = sample defect rate • Average sample defect rate • St dev of sample defect rate • Define control limits 17 Stephen Shum Spring 2009 Plotting the Plotting the p-chart Period 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 n 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 defects 18 15 18 6 20 16 16 19 20 16 10 14 21 13 13 13 17 17 21 18 16 14 33 46 10 12 13 18 19 14 p 0.060 0. 050 0.060 0.020 0.067 0.053 0.053 0. 063 0.067 0.053 0.033 0.047 0.070 0.043 0.043 0.043 0.057 0.057 0. 070 0.060 0.053 0.047 0.110 0.153 0. 033 0.040 0.043 0.060 0.063 0.047 0.180 0.160 Out of control of 0.140 0.120 0.100 0.080 0.060 0.040 0.020 0.000 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 18 Stephen Shum Spring 2009 Example Example 2: Spreadabilit of Peanut Butter bility Spreadability of peanut butter is an...
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This note was uploaded on 02/20/2013 for the course ISOM 161 taught by Professor Manyu during the Fall '09 term at HKU.

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