Interrelationship Digraph Source
This posting gives the background and source of the interrelationship digraph. It differentiates this source from the ‘Seven major SPC Tools’ and the ‘Magnificent Seven’.GOAL/QPC, an educational...
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Box Plot
This posting describes the Box Plot (Box-and-whiskers plot) which is a tool for use in the seventh step, Study Cause and Effect, of the Hoerl-Snee Process Improvement Strategy. The posting defines the...
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Multi-Vari Chart
This posting describes the Multi-Vari Chart which is a tool for use in the seventh step, Study Cause and Effect, of the Hoerl-Snee Process Improvement Strategy. The posting defines the chart and...
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Simulation Model Building
This posting illustrates the use of model building to study cause and effect and reduce common-cause variation. One approach to model building is to build a model such as a regression model based on...
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Design of Experiments: Grinding Process Example (Part 1)
This posting describes a grinding process case study to illustrate the use of design and analysis of experiments to study cause and effect and reduce common-cause variation. We continue the case study...
View ArticleDesign of Experiments: Grinding Process Example (Part 2)
This posting continues the grinding process case study (Gigo, 2008) that illustrates the use of design and analysis of experiments to reduce common-cause variation. The 9/15/2008 posting initiated the...
View ArticleDesign of Experiments: Grinding Process Example (Part 3)
This posting continues the grinding process case study (Gigo, 2008) that illustrates the use of design and analysis of experiments to reduce common-cause variation. We examine the properties of the...
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Design of Experiments: Grinding Process Example (Part 4)
This posting continues the grinding process case study (Gigo, 2008) that illustrates the use of design and analysis of experiments to reduce common-cause variation. We present the results of the...
View ArticleExploratory and Confirmatory Data Analyses
This posting describes the difference between Exploratory Data Analysis (EDA) and Confirmatory Data Analysis (CDA). Tukey (1977) distinguished between EDA and CDA. Confirmatory Data Analysis tests...
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Exploratory Data Analysis: Molding Operation Example
The purpose of Exploratory Data Analysis (EDA) is to generate hypotheses or clues that guide us in improving quality or process performance. Breyfogle (2003, pgs. 10-11) views Six Sigma as a murder...
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Exploratory Data Analysis: Defect Reduction Example
Bisgaard (2006) gives us an example where Exploratory Data Analysis leads us to narrow the scope of the quality improvement investigation. The example involves the production of small outboard motors...
View ArticleExploratory Data Analysis: Resin Output Variation Example
The postings on 3/21/2008, 3/25/2008, 3/28/2008 and 4/1/2008 present the Resin Output Variation Example to illustrate Statistical Thinking and the Hoerl-Snee Process Improvement Strategy. This...
View ArticleExploratory Data Analysis: Key Steps
De Mast and Trip (2007) list the following three steps in performing Exploratory Data Analysis.Display the DataIdentify salient featuresInterpret salient featuresThe resin output variation example,...
View ArticleExploratory Data Analysis: Limitations
De Mast and Trip (2007) specify that the purpose of Exploratory Data Analysis (EDA) is to identify the dependent (Y) and independent (X) variables that may help understand or solve a quality problem....
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Exploratory Data Analysis: Stratification
The primary purpose Exploratory Data Analysis (EDA) is to identify the key variables that affect the quality measures. Two principles, mentioned by De Mast and Trip (2007), are helpful in identifying...
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