Name
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The system enters numeric names for
metrics. The same name is used for all metrics in a CTQ but each metric is
appended with a sequential number.
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Source
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A metric's source can be Goal, Predicted,
Allocated, Measured, or Controlled.
For a description of these metrics, see
Quality Metrics and Their Sources.
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Date
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The date on which the metric was added.
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For discrete CTQs:
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- DPMO. Defects Per Million
Opportunities. The average number of defects per unit observed during an
average production run divided by the number of opportunities to make a defect
on the product under study during that run normalized to one million.
- DPU. Defects Per Unit is the
average number of defects observed when sampling a population.
DPU = Total # of Defects / Total
population
- Sigma. Calculated as
NORMSINV(1-((Total Defects) / (Total
Opportunities))) + 1.5
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For continuous CTQs:
- Mean.
- Standard Deviation
- Upper Spec Limit
- Lower Spec Limit
- Sigma.
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- Mean. The required mean for the
end of the project. The mean is the average data point value within a data set.
To calculate the mean, add all of the individual data points then divide that
figure by the total number of data points.
- Standard Deviation. The required
standard deviation for the end of the project. Standard deviation is a
statistic used to measure the variation in a distribution. Sample standard
deviation is equal to the square root of (the sum of the squared deviations of
the mean divided by the sample size minus 1).
- Upper Spec Limit. The required
upper specification limit for the end of the project, as specified by the
customer.
- Lower Spec Limit. The required
lower specification limit for the end of the project, as specified by the
customer.
- Sigma. Calculated as
NORMSINV(1-((Total Defects) / (Total
Opportunities))) + 1.5
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Originator
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The user name for the person who added the
metric.
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Comments
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Comments about the quality metric.
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