Noise Variable A nuisance or
uncontrolled factor that adds variation to a process or product.
Non-Value-Added An operation
that does not transform the product in a way that is meaningful to the customer
and is not needed for operational success.
Null Hypothesis Statement of
no change or difference. The default is to assume the Null Hypothesis to
be true unless refuted by sufficient evidence.If the Null Hypothesis is refuted, the Alternate Hypothesis is accepted
instead, with a certain level of confidence.
Number of Distinct Categories Ratio of the
standard deviation of the parts to standard deviation of the measurement
OFAT An experiment
strategy that changes one factor at a time to evaluate its effects on an
output. An OFAT experimental strategy can be inefficient in terms of requiring
more runs than a DOE approach, and can miss interactions and the optimal
One Way ANOVA An analysis
technique for determining whether any mean is significantly different from
other means, and for evaluating single factor experiments.
P- & NP-Charts Control charts
Passive Opportunities Parts +
PLEX A process
improvement tool for on-line use in full production.
Poisson Distribution Probability
function that is used for charts for defects.
error-proofing, A control method that makes it very unlikely or impossible for
an error to occur.
Polynomial Model A mathematical
model or equation in which the response is a described as a function of input
factors and input factors raised to integer exponents, such as input factors
squared:Y= b0 + b1 X1 + b2 X1^2 +
Population Parameter Fixed, but
unknown characteristics describing the distribution for all values of an entire
Population Variance The average of
the squared deviation of each individual data points from the population mean
for all values of an entire group.
Positional Variation Within piece
probability of detecting a real difference, or 100% minus the Beta risk, the
risk of incorrectly concluding that there is no difference.
Ppk The distance
between the mean and the nearest specification limit divided by (3 x long term
standard deviation ).
Precision The total
variation due to the measurement system.
Pre-control A technique of
controlling processes that do not run at steady state.
Primary Metric A gauge used
to measure project progress (dpu, RTY, etc.).
Process Consists of input, value-add, and output.
Process Flow Diagram A detailed map
of every step in the process, including hidden factory steps.
Process Improvement Successful projects will
improve quality, delight the customer, enhance employee development, increase
process effectiveness & efficiency, and result in greater corporate profit,
and a higher return on investment (ROI).
Project Team Performs the process improvement tasks.
Process Improvement Methodology The tactics of Six Sigma
Pure Error The variation
in the data that is estimated by repeat runs.
Randomized Block Design An experiment
containing two sets of categorical inputs, one set of which consists of noise
Range The numerical
distance between the highest and lowest values in a data set.
Red Tagging A technique
used for sorting the necessary from the unnecessary.
Reduced Model The best-fit
predictive equation using only the statistically significant factors and
Region of Curvature The region
where one or more significant inputs no longer conforms to a linear model.
Regression Equation A prediction
equation which allows values of inputs to be used to predict the value of
Repeatability The inherent
variability of the measurement device. The variability of measurements
under similar conditions such as the same operator and same measurement device.
runs using the same combination of treatments, run consecutively without new
Replicates The number of
times the entire experiment is repeated. Combinations
are not run consecutively.
variability of a measurement device when measurements are made under different
conditions such as with different operators or different measurement devices.
Residuals The difference
between the expected value from a model and the experimental data value.
Response Surface The surface of
the expected value of an output or response modeled as a function of
Risk Priority Number An index used
in FMEA (Failure Modes and Effects Analysis) to prioritize possible failure
conditions, calculated as the product of Severity x Occurrence x Detection
Difficulty. If Severity, Probability of Occurrence and Detection difficulty are
each evaluated on a 1-10 scale, then the Risk Priority Number can range from 1