Question 1

Discuss the difference between a continuous metric and a discrete metric, give examples of each, and list the common control charts associated with each.

Accepted Answer

A continuous metric is one that is calculated from data that are measured as the degree of conformance to a specification on some continuous scale of measurement. Examples are length, weight, and time. Customer waiting time and order lead time are other examples. Continuous data usually require x-bar and R charts.
A discrete metric is one that is calculated from data that are counted. A dimension on a machined part is either within tolerance or out of tolerance, an order is either complete or incomplete, or a customer made a complaint or not about a service experience. We can count the percentage or number of parts within tolerance, the percentage or number of complete orders, and the percentage or number of complaints. These examples usually require a p- or c-charts.

Question 2

Historically, the average proportion of defective bars has been 0.015. Samples of 100 bars each are taken. Construct a p-chart using z = 3. Suppose a sample had 0.044 defectives. What would you do?

Accepted Answer

A) Nothing; it appears to be random variation. 
B) Look for assignable causes. 
C) Delete the sample with 0.044 defects and take another sample that is better. 
D) None of these choices 
A) Nothing; it appears to be random variation. 
B) Look for assignable causes. 
C) Delete the sample with 0.044 defects and take another sample that is better. 
D) None of these choices A

Question 3

Evaluating the trade-offs between the costs of detecting and replacing a defective part or allowing it to continue on through the production process is related to

Accepted Answer

A) Supplier certification and management 
B) In-process control 
C) Finished goods control 
D) Statistical process control 
A) Supplier certification and management 
B) In-process control 
C) Finished goods control 
D) Statistical process control B

Question 4

A c-chart is used to monitor the fraction nonconforming, whereas a p-chart monitors the number of nonconformances per unit.

Accepted Answer

A) True 
 B)False

Question 5

The time to check out guests at a hotel was measured over the course of several weeks. Management believes that the target time for checking out guests should be between 2 and 4 minutes with a target of 3 minutes. The data gathered had a mean time of 2.75 minutes with a standard deviation of 0.4 minutes. Find and interpret Cp, Cpl, Cpu, and Cpk in the context of this situation.

Accepted Answer

C_p =( UTL - LTL) /6 @#LAT-DLM& = (4 - 2

Question 6

Testing whether a computer boots up the first time is an example of

Accepted Answer

A) Supplier certification and management 
B) In-process control 
C) Finished goods control 
D) Statistical process control 
A) Supplier certification and management 
B) In-process control 
C) Finished goods control 
D) Statistical process control

Question 7

Collecting continuous data is usually easier than collecting discrete data.

Accepted Answer

A) True 
 B)False

Question 8

Quality control of front-office operations in services can effectively use many of the same techniques that are applied in manufacturing.

Accepted Answer

A) True 
 B)False

Question 9

If one was monitoring the average time to load a web page, the chart to use would be the

Accepted Answer

A) -chart 
B) R-chart 
C) p-chart 
D) c-chart 
A) -chart 
B) R-chart 
C) p-chart 
D) c-chart

Question 10

Define and give an example of the three components of any control system.

Accepted Answer

The three components of any control syst

Question 11

Statistical calculations will show that if p = .01, then the sample size needed to have at least a 95% chance of finding at least one nonconformance is

Accepted Answer

A) 30 
B) 100 
C) 300 
D) 1,000 
A) 30 
B) 100 
C) 300 
D) 1,000

Question 12

If process quality approaches six sigma levels, then standard types of control charts are not useful.

Accepted Answer

A) True 
 B)False

Question 13

A company is measuring the time it takes to complete an order. Twenty five samples of size 6 resulted in an average time of 80 minutes with an average range of 20 minutes. Find control limits for the appropriate control charts) that would be used to monitor this process.

Accepted Answer

Because the measurement is a continuous

Question 14

A company that manufactures arrows for sale in archery stores is developing a new arrow with enhanced flight characteristics. From customer surveys the company has determined that the diameter of the arrow should be between 10.0 and 10.6 mm. They want to ensure the process they develop to produce the arrows will meet customer expectations; that is, the process capability index (Cp) will be greater than or equal to 1.00.
a. What value of the standard deviation of the process will yield a Cp equal to 1.00?
b. If the standard deviation of the process is actually .05, what would the diameter variation (UTL- LTL) of the arrow have to be to get a Cp of 1.00?

Accepted Answer

a. Std. dev. of process = (UTL

Question 15

Process capability quantifies the variation that results from common causes.

Accepted Answer

A) True 
 B)False

Question 16

Over-adjusting a process that is in control will usually increase the variation in the output.

Accepted Answer

A) True 
 B)False

Question 17

Define Statistical Process Control (SPC) and differentiate between common cause and (special or assignable) cause variation.

Accepted Answer

Statistical Process Control( SPC) is a m

Question 18

An operator has determined what her percent defectives is for the machine which she operates. Based on several samples of 75 observations, she found p-bar to be 10%. She wants to set up a control chart using 3 standard deviation control limits.
a. What is the upper control limit for a p chart?
b. What is the lower control limit for a p chart?

Accepted Answer

The answer of An operator has determined what her percent...

Question 19

Over several days, 25 samples of 100 items each were tested for electrical resistance. A total of 60 items failed. Determine $\bar { p }$ and the control limits for a p chart.

Accepted Answer

p-bar = 60/(25 x 100) = 0.024

Question 20

Five samples were taken, with five observations each. The sample findings are listed below. The sample values represent service times in minutes.
 $\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\quad $$\text { Observation Number }$
$\begin{array}{lccccc}
\text { Sample Number }&1&2&3&4&5\
\hline1 & 10.1 & 10.6 & 9.8 & 9.9 & 10.5 \
2 & 9.7 & 9.5 & 10.3 & 9.9 & 10.5 \
3 & 10.1 & 10.7 & 9.2 & 10.0 & 10.1 \
4 & 9.9 & 9.8 & 10.5 & 10.4 & 10.1 \
5 & 10.4 & 10.1 & 10.9 & 9.9 & 10.1
\end{array}$ 
a. Determine the control limits for the R-chart.
b. Would you conclude the R-chart is in statistical control and proceed to develop the x-bar chart?

Accepted Answer

a. R₁ = 1.1, R₂ = 1.0, R₃ = 1.5, R₄ = 0.7, R

Discuss the difference between a continuous metric and a discrete metric, give examples of each, and list the common control charts associated with each.

Historically, the average proportion of defective bars has been 0.015. Samples of 100 bars each are taken. Construct a p-chart using z = 3. Suppose a sample had 0.044 defectives. What would you do?

Evaluating the trade-offs between the costs of detecting and replacing a defective part or allowing it to continue on through the production process is related to

A c-chart is used to monitor the fraction nonconforming, whereas a p-chart monitors the number of nonconformances per unit.

Testing whether a computer boots up the first time is an example of

Collecting continuous data is usually easier than collecting discrete data.

Quality control of front-office operations in services can effectively use many of the same techniques that are applied in manufacturing.

If one was monitoring the average time to load a web page, the chart to use would be the

Define and give an example of the three components of any control system.

Statistical calculations will show that if p = .01, then the sample size needed to have at least a 95% chance of finding at least one nonconformance is

If process quality approaches six sigma levels, then standard types of control charts are not useful.

A company is measuring the time it takes to complete an order. Twenty five samples of size 6 resulted in an average time of 80 minutes with an average range of 20 minutes. Find control limits for the appropriate control charts) that would be used to monitor this process.

Process capability quantifies the variation that results from common causes.

Over-adjusting a process that is in control will usually increase the variation in the output.

Define Statistical Process Control (SPC) and differentiate between common cause and (special or assignable) cause variation.

Over several days, 25 samples of 100 items each were tested for electrical resistance. A total of 60 items failed. Determine $\bar { p }$ and the control limits for a p chart.

Goods, Services, and Operations Management

Value Chains

Measuring Performance in Operations

Operations Strategy

Technology and Operations Management

Goods and Service Design

Process Selection, Design, and Analysis

Facility and Work Design

Supply Chain Design

Capacity Management

Forecasting and Demand Planning

Managing Inventories

Resource Management

Operations Scheduling and Sequencing

Quality Management

Lean Operating Systems

Project Management

Work Measurement, Learning Curves, and Standards

Queuing Analysis

Modeling Using Linear Programming

Simulation

Work Measurement, Learning Curves, and Standards

Filters

Exam 16: Quality Control and Spc

Discuss the difference between a continuous metric and a discrete metric, give examples of each, and list the common control charts associated with each.

Historically, the average proportion of defective bars has been 0.015. Samples of 100 bars each are taken. Construct a p-chart using z = 3. Suppose a sample had 0.044 defectives. What would you do?

Evaluating the trade-offs between the costs of detecting and replacing a defective part or allowing it to continue on through the production process is related to

A c-chart is used to monitor the fraction nonconforming, whereas a p-chart monitors the number of nonconformances per unit.

Testing whether a computer boots up the first time is an example of

Collecting continuous data is usually easier than collecting discrete data.

Quality control of front-office operations in services can effectively use many of the same techniques that are applied in manufacturing.

If one was monitoring the average time to load a web page, the chart to use would be the

Define and give an example of the three components of any control system.

Statistical calculations will show that if p = .01, then the sample size needed to have at least a 95% chance of finding at least one nonconformance is

If process quality approaches six sigma levels, then standard types of control charts are not useful.

A company is measuring the time it takes to complete an order. Twenty five samples of size 6 resulted in an average time of 80 minutes with an average range of 20 minutes. Find control limits for the appropriate control charts) that would be used to monitor this process.

Process capability quantifies the variation that results from common causes.

Over-adjusting a process that is in control will usually increase the variation in the output.

Define Statistical Process Control (SPC) and differentiate between common cause and (special or assignable) cause variation.

Over several days, 25 samples of 100 items each were tested for electrical resistance. A total of 60 items failed. Determine pˉ\bar { p }pˉ​ and the control limits for a p chart.

Goods, Services, and Operations Management

Value Chains

Measuring Performance in Operations

Operations Strategy

Technology and Operations Management

Goods and Service Design

Process Selection, Design, and Analysis

Facility and Work Design

Supply Chain Design

Capacity Management

Forecasting and Demand Planning

Managing Inventories

Resource Management

Operations Scheduling and Sequencing

Quality Management

Lean Operating Systems

Project Management

Work Measurement, Learning Curves, and Standards

Queuing Analysis

Modeling Using Linear Programming

Simulation

Work Measurement, Learning Curves, and Standards

Filters

Over several days, 25 samples of 100 items each were tested for electrical resistance. A total of 60 items failed. Determine $\bar { p }$ and the control limits for a p chart.