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Quality Control Quality Control Table Of Contents Quality Planning Tools........................................................................................................................................................... 1 Overview........................................................................................................................................................................... 1 Run Chart ......................................................................................................................................................................... 2 Pareto Chart ..................................................................................................................................................................... 5 Cause-and-Effect Diagram............................................................................................................................................... 9 Multi-Vari Chart............................................................................................................................................................... 13 Symmetry Plot ................................................................................................................................................................ 14 Control Charts...................................................................................................................................................................... 19 Overview......................................................................................................................................................................... 19 Box-Cox Transformation................................................................................................................................................. 25 Variables Charts for Subgroups ..................................................................................................................................... 27 Variables Charts for Individuals...................................................................................................................................... 90 Attributes Charts........................................................................................................................................................... 123 Time-weighted Charts .................................................................................................................................................. 152 Multivariate Charts........................................................................................................................................................ 177 Measurement Systems Analysis........................................................................................................................................ 209 Overview....................................................................................................................................................................... 209 Gage Run Chart ........................................................................................................................................................... 211 Gage Linearity and Bias Study..................................................................................................................................... 214 Gage R&R Study (Crossed) ......................................................................................................................................... 216 Gage R&R Study (Nested) ........................................................................................................................................... 225 Attribute Agreement Analysis ....................................................................................................................................... 229 Attribute Gage Study (Analytic Method) ....................................................................................................................... 235 Process Capability ............................................................................................................................................................. 239 Overview....................................................................................................................................................................... 239 Individual Distribution Identification .............................................................................................................................. 245 Johnson Transformation............................................................................................................................................... 250 Capability Analysis - Normal......................................................................................................................................... 253 Capability Analysis - Between/Within ........................................................................................................................... 260 Capability Analysis - Nonnormal .................................................................................................................................. 264 Capability Analysis for Multiple Variables - Normal...................................................................................................... 269 Capability Analysis for Multiple Variables - Nonnormal................................................................................................ 278 Capability Analysis - Binomial ...................................................................................................................................... 285 Capability Analysis - Poisson ....................................................................................................................................... 289 Capability Sixpack - Normal ......................................................................................................................................... 293 Capability Sixpack - Between/Within............................................................................................................................ 298 Capability Sixpack - Nonnormal ................................................................................................................................... 302 Index .................................................................................................................................................................................. 305 2003 Minitab Inc. i Quality Planning Tools Overview Quality Planning Tool Minitab offers several graphical tools to help you explore and detect quality problems and improve your process: Run charts detect patterns in your process data, and perform two tests for non-random behavior. Pareto charts help you identify which of your problems are most significant, so you can focus improvement efforts on areas where the largest gains can be made. Cause-and-effect (fishbone) diagrams can help you organize brainstorming information about the potential causes of a problem. Multi-vari charts present analysis of variance data in graphical form to give you a "look" at your data. Symmetry plots can help you assess whether your data come from a symmetric distribution. Quality Tools Stat > Quality Tools Choose one of the following: Run Chart Pareto Chart Cause-and-Effect Individual Distribution Identification Johnson Transformation Capability Analysis Normal Between/Within Nonnormal Multiple Variables (Normal) Multiple Variables (Nonnormal) Binomial Poisson Capability Sixpack Normal Nonnormal Between/Within Gage Study Gage Run Chart Gage Linearity and Bias Study Gage R&R Study (Crossed) Gage R&R Study (Nested) Attribute Gage Study (Analytic Method) Attribute Agreement Analysis Multi-Vari Chart Symmetry Plot 2003 Minitab Inc. 1 Quality Control Examples of Quality Tools The following examples illustrate how to use the various quality tools. Choose an example below: Run Chart Pareto Chart Cause-and-Effect Individual Distribution Identification Johnson Transformation Capability Analysis Capability Sixpack Gage Run Chart Gage Linearity and Bias Study Gage R&R Study (Crossed) (ANOVA method) Gage R&R Study (Crossed) (X-bar and R method) Gage R&R Study (Nested) Attribute Gage Study (Analytic Method) Attribute Agreement Analysis Multi-Vari Chart Symmetry Plot References − Quality Tools [1] J.D. Gibbons (1986). "Randomness, Tests of," Encyclopedia of Statistical Sciences, 7, 555−562. [2] T.P. Ryan (1989). Statistical Methods for Quality Improvement. John Wiley & Sons. [3] W.A. Taylor (1991). Optimization & Variation Reduction in Quality. McGraw-Hill, Inc. Run Chart Run Chart Overview Variation occurs in all processes. Common cause variation is a natural part of the process. Another type of variation, called special causes, comes from outside the system and causes recognizable patterns, shifts, or trends in the data. The run chart shows if special causes are influencing your process. A process is in control when only common causes affect the process output. Run Chart performs two tests for randomness that provide information on the non-random variation due to trends, oscillation, mixtures, and clustering. For details, see Using the Tests for Randomness. Run Chart Stat > Quality Tools > Run Chart Use Run Chart to look for evidence of patterns in your process data, and perform two tests for non-random behavior. Run Chart plots all of the individual observations versus the subgroup number,
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