Ch. 6 Flashcards
Statistical Process Control
inspecting a random sample to determine if it produces products within a predetermined range
Two causes of Variation
common and assignable
Ex. of Common Variation
slight differences in materials, workers, machines, tools, and other factors
Common Variation
random, unidentifiable
Assignable Variation
identifiable, can be eliminated
Out of control
when a plot of data falls outside the preset control limits
Control chart for Variables
used to monitor characteristics that can be measured and have a continuous scale
Control chart for Attributes
used to monitor characteristics that have discrete values and can be counted
Process width when computing the process capability index?
6
Acceptance Sampling is done when?
done before or after the process
Acceptance Sampling
process of randomly inspecting a certain number of items from a batch to know if the entire batch should be accepted or rejected
Why have services lagged behind manufacturing in statistical process control?
it is difficult to measure the quality of a service
The issue that complicates service quality control?
the presence of the customer at time of service delivery
Six Sigma Quality
3.4 million
X-bar chart
control chart used to monitor changes in the mean value
Statistical process control (SPC)
inspects a random sample of the output of the process and decides whether the process is producing within the characteristics and range given
Statistical quality control (SQC)
general category of statistical tools to evaluate organizational quality
Sampling plan
precisely specifies the parameters of sampling process with acceptance/rejection criteria
Range (R) chart
control chart that monitors changes in the dispersion of a process
Producers risk
chance that a lot containing an acceptable quality level will be rejected
P-chart
monitors the proportion of defects in a sample
Operating Characterize (OC) Curve
graph that shows the probability of accepting a lot given various proportions of defects in a lot
Lot Tolerance Percent Defective (LTPD)
upper limit of percentage of defective items consumers are willing to tolerate
Consumer Risk
chance of accepting a lot that contains a greater number of defects than the LTPD limit
C-chart
monitors the number of defects per unit
Average Outgoing Quality (AOQ)
expected proportion of defective items that will be passed to the customer under the sampling plan
Attribute
characteristic that has a discrete value and can be counted
