Quality Management 2017
A NALYZE
5. Characterization of the data distribution
• Statistical tests to verify the normality of the data
Part 1 :
Graphical method : Henry line, Quantile-Quantile plot (Q-Q plot)
Introduction to SPC
✓ Aligned points Hypothesis of a normal distribution ✓ Can be done without any particular sofware.
Part 2 :
Essential concepts to start with SPC
Intervals
✓ Not as powerful as numerical tests.
Cumulative percentages
Part 3 :
Numerical methods : Shapiro-Wilk test, Anderson-Darling test, Kolmogorov test… ✓ Statistical softwares can easily do those tests ✓ The value of p-value measures how far the data is from a normal distribution. ✓ Choice depends on your data
SPC in practice
Part 4
Conclusion
03/10/17
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