# Statistics Spotlight

## 1999

### Statistical process control--a glimpse at its past and future.

The index Cp = ( USL - LSL)/ 6. = ( specification tolerance)/ 6.., where USL and LSL are the upper specification 54 I Q U A L I T Y P R O G R E S S I D E C E M B E R 1 9 9 9 Statistical Process Control A glimpse at its past and future by J. Stuart Hunter...

### Comparing the Importance of Variation And Mean of a Distribution

An industrial case study

Capability studies indicate benefits of both methods Capability studies typically assume the data is normally distributed, but the measurement device was only 90 I Q U A L I T Y P R O G R E S S I O C T O B E R 1 9 9 9 Comparing the Importance of Variatio...

### Why Should Statisticians Pay Attention to Six Sigma?

An Examiniation for Their Role in Six Sigma Methodology

At first, one might conclude that the six sigma methodology is nothing new. It uses statistical methods that have already been proven. It focuses on quality improvement and defect reduction and utilizes project-by-project improvement...

### Why Should Statisticians Pay Attention to Six Sigma?

An examination for their role in the six sigma methodology

12. Hoerl and Snee, " Redesigning the Introductory Statistics Course" ( see reference 3). 13. Mikel J. Harry, The Vision of Six Sigma: A Roadmap for Breakthrough ( Phoenix: Sigma Publishing Co., 1994). 14. Mikel J. Harry, This Vision of Six Sigma: Tools ...

### Burn the Brownies

Effective experimental design through statistical thinking.

92 I Q U A L I T Y P R O G R E S S I A U G U S T 1 9 9 9 Burn the Brownies Effective experimental design through statistical thinking by Lynne B. Hare Statistics Roundtable High amount of chocolate Strength of chocolate flavor Temperature Regular High Re...

### Reliability Improvement Issues and Tools

Weibull distributions can also represent products with either a decreasing hazard rate ( less than 1) or increasing hazard rate ( greater than 1). When equals 1 the Q U A L I T Y P R O G R E S S I M A Y 1 9 9 9 I 135 Selling Reliability to Upper Manageme...

### Statistical Gymnastics Revisited

A debate on one approach to short-run control charts

Summarizing the results by the medians and the first and third quartiles, I found: 10 Subsamples true median Q1 Q3 x0 0.0027 0.0067 0.0028 0.0157 x1 0.2225 0.2289 0.1119 0.3962 x2 0.9295 0.9324 0.8460 0.9757 v0 0.0027 0.0029 0.0023 0.0054 v1 0.1177 0.122...

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