How do I: Determine Sample size, Number of Trials and Appraisers for MSA

[Raghav]

On what basis do we set
# sample size/ subgroup size for control charts (stability study)
# number of trials for bias/linearity/R&R studies
# number of appraisers for R&R

 

[Al Dyer]

Raghav:

# sample size/ subgroup size for control charts (stability study)

*5 ongoing, we chart weekly to look for trends.
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# number of trials for bias/linearity/R&R studies

*Bias = 1 part (could use an XR chart over time.

*Linearity = 1 part measuring bias over the travel range of the gage

*R&R = 3 people measuring 10 sequentially numbered parts.
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# number of appraisers for R&R

*3
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These are very basic guidelines that can be revised based on the type and application of the gage.

ASD...