Question 1

When using a cause-and-effect diagram in process diagnosis, you begin by specifying the cause of interest and then move forward to identify potential effects of this cause.

Accepted Answer

A cause-and-effect diagram, also known as a fishbone diagram, starts with the effect or problem and then works backward to identify potential causes.

Question 2

The elimination of common causes of variation is typically the responsibility of workers, not management.

Accepted Answer

The elimination of common causes of variation is typically the responsibility of management, as it involves systemic changes to processes and systems.

Question 3

The p-chart is based on the assumption that the number of defective units in each sample is a binomial random variable.

Accepted Answer

The p-chart is used for monitoring the proportion of defective units in a process, and it assumes that the number of defective units follows a binomial distribution, where each unit can be classified as defective or non-defective.

Question 4

The variation in the output of processes that are out of control can be entirely attributed to random behavior.

Accepted Answer

Processes that are out of control have variations due to assignable causes, not just random behavior.

Question 5

The distribution that describes the output variable of a process may change over time.

Accepted Answer

The distribution of an output variable can change over time due to various factors such as changes in the process, environment, or external influences, leading to what is known as "concept drift."

Question 6

Statistical process control consists of monitoring process variation, diagnosing causes of variation, and eliminating those causes.

Accepted Answer

Statistical process control (SPC) is a method used in quality control that involves monitoring and controlling a process to ensure that it operates at its full potential. It includes identifying variations, diagnosing their causes, and implementing solutions to eliminate them.

Question 7

A process may be in control but still not be capable of producing output that is acceptable to customers.

Accepted Answer

A process can be stable and predictable (in control) but may not meet customer specifications if the process mean or variability does not align with customer requirements.

Question 8

A process is in control and has a normally distributed output distribution with mean of 1000 and a standard deviation of 100 . The upper and lower specification limits for the process are 1060 and 940 , respectively. Find the $\mathrm { C } _ { \mathrm { p } }$ value of the process. Is the system capable?
A) $\mathrm { C } _ { \mathrm { p } } = 0.2$; the system is capable.
B) $\mathrm { C } _ { \mathrm { p } } = 3.333$; the system is not capable.
C) $C _ { p } = 3.333$; the system is capable.
D) $\mathrm { C } _ { \mathrm { p } } = 0.2$; the system is not capable.

Accepted Answer

The answer of A process is in control and has...

Question 9

Find the process spread when $\sigma = 13$
A) 39
B) 156
C) 26
D) 78

Accepted Answer

The process spread is typically calculated as 6 times the standard deviation ($\sigma$), so $6 \times 13 = 78$.

Question 10

If the R-chart indicates that the process variation is in control, then it makes sense to construct and interpret the $\overline { \mathrm { X } }$ chart.

Accepted Answer

If the R-chart shows that the process variation is stable and in control, it is appropriate to use the $\overline { \mathrm { X } }$ chart to monitor the process mean, as the assumption of stable variation is necessary for accurate interpretation of the $\overline { \mathrm { X } }$ chart.

Question 11

An in-control, centered process that follows a normal distribution has a $C _ { p }$ of 3.0. How many standard deviations away from the process mean is the upper specification limit?
A) 9
B) 3
C) 18
D) 6

Accepted Answer

The $C _ { p }$ is defined as:$$C _ { p } = \frac { USL - LSL } { 6 \sigma }$$where $USL$ is the upper specification limit, $LSL$ is the lower specification limit, and $\sigma$ is the standard deviation.In this case, $C _ { p } = 3.0$, so:$$3.0 = \frac { USL - LSL } { 6 \sigma }$$$$USL - LSL = 18 \sigma$$Since the process is centered, $LSL = -USL$. Therefore:$$USL = 9 \sigma$$So the upper specification limit is 9 standard deviations away from the process mean.

Question 12

An unbiased estimator for ? can be found by dividing the mean of the ranges, $\overline { \mathrm { R } }$ by an appropriate constant.

Accepted Answer

The mean of the ranges divided by an appropriate constant can serve as an unbiased estimator for the population standard deviation in statistical quality control, specifically in the context of control charts.

Question 13

Conformance refers to the extent to which a good or service can be adapted for use in new situations.

Accepted Answer

Conformance refers to the degree to which a product or service meets specified standards or requirements, not its adaptability to new situations.

Question 14

Estimate the process spread when s $s = 0.0032$
A) 0.0096
B) 0.0064
C) 0.0384
D) 0.0192

Accepted Answer

The process spread is typically estimated as 6 times the standard deviation (s). Therefore, 6 * 0.0032 = 0.0192.

Question 15

In constructing a p-chart, it is advisable to use a much smaller sample size than is typically used for $\bar { x } -$ and R-charts.

Accepted Answer

P-charts require larger sample sizes to accurately estimate the proportion of defects, unlike $\bar{x}$ and R-charts which can work with smaller sample sizes for monitoring process averages and variability.

Question 16

The diagnosis phase of statistical process control is concerned with tracking down causes of variation.

Accepted Answer

The diagnosis phase in statistical process control involves identifying and understanding the sources of variation in a process to implement corrective actions.

Question 17

When constructing an $\bar { x }$-chart, $\bar{\bar { x }}$ is used as the estimator of $\mu$.

Accepted Answer

The answer of When constructing an $\bar { x }$-chart,...

Question 18

Performance, reliability, and durability are some of the factors used to evaluate quality.

Accepted Answer

Performance, reliability, and durability are key factors in assessing the quality of a product or service, as they determine how well it meets user needs and expectations over time.

Question 19

A process adds value to the inputs of the process.

Accepted Answer

A process transforms inputs into outputs by adding value, which is the essence of a process in business or production contexts.

Question 20

(Situation B) A manufacturing company makes hemostats for hospital emergency rooms. The company is interested in implementing statistical process control procedures in its production operation. The production manager believes that the proportion of defective hemostats generated by the process is about 3%. The company collected one sample of 300
consecutively manufactured hemostats each day for 20 days. The data are shown below. $$\begin{array} { c c c c c c } 
\hline \text { Sample } & \text { Sample Size } & \text { Defectives } & \text { Sample } & \text { Sample Size } & \text { Defectives } \
\hline 1 & 300 & 8 & 11 & 300 & 12 \
2 & 300 & 6 & 12 & 300 & 11 \
3 & 300 & 11 & 13 & 300 & 14 \
4 & 300 & 15 & 14 & 300 & 8 \
5 & 300 & 12 & 15 & 300 & 7 \
6 & 300 & 11 & 16 & 300 & 3 \
7 & 300 & 9 & 17 & 300 & 9 \
8 & 300 & 6 & 18 & 300 & 11 \
9 & 300 & 5 & 19 & 300 & 10 \
10 & 300 & 4 & 20 & 300 & 6 \
\hline
\end{array}$$
-Calculate the centerline used in constructing a  $\mathrm { p } \text {-chart. }$
A) .0317
B) .0297
C) .0593
D) .0245

Accepted Answer

The answer of (Situation B) A manufacturing company makes hemostats...

Quiz 13: Methods for Quality Improvement: Statistical Process Control Available on CD

When using a cause-and-effect diagram in process diagnosis, you begin by specifying the cause of interest and then move forward to identify potential effects of this cause.

The elimination of common causes of variation is typically the responsibility of workers, not management.

The p-chart is based on the assumption that the number of defective units in each sample is a binomial random variable.

The variation in the output of processes that are out of control can be entirely attributed to random behavior.

The distribution that describes the output variable of a process may change over time.

Statistical process control consists of monitoring process variation, diagnosing causes of variation, and eliminating those causes.

A process may be in control but still not be capable of producing output that is acceptable to customers.

Find the process spread when $\sigma = 13$

If the R-chart indicates that the process variation is in control, then it makes sense to construct and interpret the $\overline { \mathrm { X } }$ chart.

An in-control, centered process that follows a normal distribution has a $C _ { p }$ of 3.0. How many standard deviations away from the process mean is the upper specification limit?

An unbiased estimator for ? can be found by dividing the mean of the ranges, $\overline { \mathrm { R } }$ by an appropriate constant.

Conformance refers to the extent to which a good or service can be adapted for use in new situations.

Estimate the process spread when s $s = 0.0032$

In constructing a p-chart, it is advisable to use a much smaller sample size than is typically used for $\bar { x } -$ and R-charts.

The diagnosis phase of statistical process control is concerned with tracking down causes of variation.

When constructing an $\bar { x }$ -chart, $\bar{\bar { x }}$ is used as the estimator of $\mu$ .

Performance, reliability, and durability are some of the factors used to evaluate quality.

A process adds value to the inputs of the process.

Quiz 13: Methods for Quality Improvement: Statistical Process Control Available on CD

When using a cause-and-effect diagram in process diagnosis, you begin by specifying the cause of interest and then move forward to identify potential effects of this cause.

The elimination of common causes of variation is typically the responsibility of workers, not management.

The p-chart is based on the assumption that the number of defective units in each sample is a binomial random variable.

The variation in the output of processes that are out of control can be entirely attributed to random behavior.

The distribution that describes the output variable of a process may change over time.

Statistical process control consists of monitoring process variation, diagnosing causes of variation, and eliminating those causes.

A process may be in control but still not be capable of producing output that is acceptable to customers.

Find the process spread when σ=13\sigma = 13σ=13

If the R-chart indicates that the process variation is in control, then it makes sense to construct and interpret the X‾\overline { \mathrm { X } }X chart.

An in-control, centered process that follows a normal distribution has a CpC _ { p }Cp​ of 3.0. How many standard deviations away from the process mean is the upper specification limit?

An unbiased estimator for ? can be found by dividing the mean of the ranges, R‾\overline { \mathrm { R } }R by an appropriate constant.

Conformance refers to the extent to which a good or service can be adapted for use in new situations.

Estimate the process spread when s s=0.0032s = 0.0032s=0.0032

In constructing a p-chart, it is advisable to use a much smaller sample size than is typically used for xˉ−\bar { x } -xˉ− and R-charts.

The diagnosis phase of statistical process control is concerned with tracking down causes of variation.

When constructing an xˉ\bar { x }xˉ -chart, xˉˉ\bar{\bar { x }}xˉˉ is used as the estimator of μ\muμ .

Performance, reliability, and durability are some of the factors used to evaluate quality.

A process adds value to the inputs of the process.

Find the process spread when $\sigma = 13$

If the R-chart indicates that the process variation is in control, then it makes sense to construct and interpret the $\overline { \mathrm { X } }$ chart.

An in-control, centered process that follows a normal distribution has a $C _ { p }$ of 3.0. How many standard deviations away from the process mean is the upper specification limit?

An unbiased estimator for ? can be found by dividing the mean of the ranges, $\overline { \mathrm { R } }$ by an appropriate constant.

Estimate the process spread when s $s = 0.0032$

In constructing a p-chart, it is advisable to use a much smaller sample size than is typically used for $\bar { x } -$ and R-charts.

When constructing an $\bar { x }$ -chart, $\bar{\bar { x }}$ is used as the estimator of $\mu$ .