Dr. Joan Burtner

1
The Certified Quality Engineer Handbook 3rd ed.
Ch. 26 Measurement System Analysis

• Dr. Joan Burtner
• Certified Quality Engineer
• Associate Professor of
• Industrial Engineering and Industrial Management

2
Ch. 26 Measurement System Analysis

• Terms and Definitions
• Gage Repeatability and Reproducibility
• Variables vs. Attributes
• Gage RR Methods
• Tabular
• Analysis of Variance
• Control Charts

2
3
Philosophy of Gage R R Studies

• Gage Repeatability and Reproducibility (RR)
  studies are used to determine if a measurement
  system is capable for its intended purpose.
• The measurement system is considered capable if
  measurement system variation is small compared to
  the process variation.
• The measurement error variance equals the sum of
  the variance due to reproducibility and the
  variance due to repeatability

3
4
Purpose of Gage R R Studies

• Determine amount of variability in the collected
  data that can be attributed to the existing
  measurement system
• Isolate the sources of variability in the
  measurement system
• Determine whether the measurement system is
  suitable for use in a broader project

4
5
Gage R R Methods

• Tabular
• Old method
• Based on control charts
• Statistically incapable of quantifying
  interaction between operators and parts
• Analysis of Variance
• Random two-factor model
• See standard experiment notation on page 261
• We will use Minitab to estimate variance effects
• We will p-values to determine significance of the
  main effects and the interaction between the
  factors

5
6
Issues and Considerations

• ANOVA applies to variables data RR studies
  for attributes data beyond the scope of the CQE
  Handbook
• Standard experiment 10 parts, three operators,
  two replicates
• Replicates vs. repeated measures?
• Restricted randomization
• There are numerous applications where complete
  randomization or true replication is not
  practical or possible. (page 269)

6