Quality Management 2017
A NALYZE
5. Characterization of the data distribution
• Build the histogram of the data:
Part 1 :
Examples of data distributions
Introduction to SPC
Truncated
Asymetric
Normal
Bi-modal
Part 2 :
Understand the shape of your data distribution. Was it expected?
Essential concepts to start with SPC
• Studied case: normal distribution Why? ✓ Most of radiotherapy processes follow a normal distribution. ✓ SPC’s traditional formulas: based on the hypothesis of a normal distribution. • Important comment: with certain precautions*, it remains possible to use SPC tools for non normal distributions (* no more link between limits of control charts and the risk, no more link between capability and % of data out of specifications)
Part 3 :
SPC in practice
Part 4
Conclusion
03/10/17
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