国外质量人员对于MSA中样品取样的理解，不知道对否？
关于样品是否必须代表整个过程的变差范围的问题，我看到其中一位同仁的答复，如下，不知道各位有什么高见。
Is your measurement system used for 1) inspection, 2) SPC/Capability studies, or 3) both?
If for 1) Inspection, part selection is not really important as the part variation is not used anywhere in the calculations. Some will recommend that you use parts from the entire tolerance because they are attempting to combine a linearity check with the R&R study. This is not necessary if linearity is checked as part of your calibration program.
If for 2) or 3), the parts should represent the actual process variation, not the range of the tolerance.
Either way, you do not need parts from the entire tolerance spread.
Is your measurement system used for 1) inspection, 2) SPC/Capability studies, or 3) both?
If for 1) Inspection, part selection is not really important as the part variation is not used anywhere in the calculations. Some will recommend that you use parts from the entire tolerance because they are attempting to combine a linearity check with the R&R study. This is not necessary if linearity is checked as part of your calibration program.
If for 2) or 3), the parts should represent the actual process variation, not the range of the tolerance.
Either way, you do not need parts from the entire tolerance spread.
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SCUGJ (威望:44) (全国 全国) 电子制造 . - Six Sigma&Data Analy...
赞同来自: joelan 、Jeanguan
The following contents are cite from AIAG MSA.
"For Product Control situations where the measurement result and
decision criteria determine, “conformance or nonconformance to
the feature specification” (i.e., 100% inspection or sampling),
samples (or standards) must be selected, but need not cover the
entire process range. The assessment of the measurement system
is based on the feature tolerance (i.e., %GRR to TOLERANCE).
For Process Control situations where the measurement result and
decision criteria determine, “process stability, direction and
compliance with the natural process variation” (i.e., SPC, process
monitoring, capability, and process improvement), the availability of
samples over the entire operating range becomes very important.
An independent estimate of process variation (process capability
study) is recommended when assessing the adequacy of the
measurement system for process control (i.e., %GRR to process
variation). "