Operations Management Exam 2
If you are going to develop an "R" chart based on range statistics and you are using a sample size of XX for your charting purposes. Which of the following is the lower control limit D3 factor for the chart?
• .18
If you are going to develop an "X-bar" chart based on range statistics and you are using a sample size of XX for your charting purposes. Which of the following is the A2 factor for the "X-bar" chart?
• .27 o X+A2R o SAMPLE SIZE= 7 o N=7 o 29,30,31. LOOKING AT CHART, READING ACROSS FOR SAMPLE SIZE
You want to develop a three-sigma "R" chart. You know the average range is XX based on several samples of size XX. Which of the following is the resulting LCL?
• 0.0
The "dimension of design quality" that Concerns the "consistency of performance" over time or the probability of failing is which of the following?
• Reliability
If you are going to develop an "R" chart based on range statistics and you are using a sample size of XX for your charting purposes. Which of the following is the upper control limit D4 factor for the chart?
1.65
A new machine has just been installed to cut and rough shape large slugs. The slugs are then transferred to a precision grinder. One of the critical measurements is the outside diameter. The quality control inspector randomly selected five slugs each hour, measured the outside diameter, and recorded the results. The measurements (in millimeters) for the period 8:00 AM to 9:30 AM follow. Note quality control constant (A2 = 0.577, D3 = 0, D4 = 2.326) Outside diameter (millimeters)
Time Period 3 samples pulled each time period X-Bar Range 8:00 X 3 X 4 X 5 4 5-3=2 8:30 X 2 X 2 X 2 2 2-2=0 9:00 X3 X4 X8 5 8-3=5 9:30 X2 X3 X4 3 4-2=2 14/4=3.5 9/4=2.25 a. Determine the control limits for the mean and the range. X-Bar chart: X-bar-bar plus/minus A2(r-bar) R-Bar chart: UCL= R-bar*D4 LCL= LCL= R-bar*d3 R BAR CHART: UCL= 2.3x 2.25= 4.5 LCL= 0 X 2.25= 0 X-BAR CHART: 3.5+.6 (2.25)= 4.8 3.5- .6(2.25)= 2 SEPARATE CHARTS • PLOT:X-BAR 4,2,5,3 • Plot range: 2,0,5,2
A FISHBONE DIAGRAM as part of a six-sigma quality improvement process might be found in which DMAIC category?
o Analyze
A FLOW CHART as part of a Six-Sigma Quality Improvement Process might be found in which DMAIC category?
o Define
A Pareto chart as part of a six-sigma quality improvement process might be found in which DMAIC category?
o Measure
Which of the following is an "analytical tool" used in six-sigma quality improvement programs?
o Pareto Chart o 80/20 rule o 20% of customers will give you 80% of profits.
You are developing an "X-bar" chart based on sample means. You know the standard deviation of the sample means is XX, the desired confidence level is XX percent(z=X), and the average of the sample means is XX. Which of the following is your UCL based on "X-Bar + 3 * standard deviation"?
• 36 o Upper limit= + o Lower limit= -
You want to develop a three-sigma "R" chart. You know the average range is XX based on several samples of size XX. Which of the following is the resulting UCL?
• 8.9 o A2, D3, D4 o UCL= D4R, LCL= D3R o R=10
You are developing an "X-bar" chart based on sample means. You know the standard deviation of the sample means is XX, the desired confidence level is XX percent, and the average of the sample means is XX. Which of the following is your LCL?
• 9.68
Quality control charts usually have a central line and upper and lower control limit lines. Which of the following are reasons that the process being monitored with the chart should be investigated?
• A single plot falls above or below the control limits.
A project starts out as which of the following?
• A statement of work= SOW
The "dimension of design quality" that Concerns the "sensory characteristics" of the product is which of the following?
• Aesthetics
Failure mode and effect analysis is used in six-sigma projects. It involves which of the following?
• Calculating a risk priority number for each possible failure/probability • Calculate risk + probability
The philosophical leaders of the quality movement, Philip Crosby, W. Edwards Deming, and Joseph M. Juran had the same general message about what it took to achieve Outstanding Quality. Which of the following was NOT part of that message?
• Cost, whether quality is free or if there is a cost to it • DMAIC= Define, Measure, Analyze, Improve, Control o Questions 11, 12, 13,
A company must perform a maintenance project consisting of seven activities. The activities, their predecessors, and their respective time estimates are presented below:
• Critical path is the longest • 2 paths, say one is 9 and one is 8. Pick 8
Which of the following is NOT an element of a Good Service Guarantee?
• Customer does not control the process, the company does, then customer follows the rules of it
Which of the following is the cost of quality classification for costs such as defects that pass through the system, such as customer warranty replacements, loss of customer or goodwill, handling complaints, and product repair?
• External Failure Costs
Which of the following is a DIMENSION of design quality?
• Features
Which of the following is the cost of quality classification for Costs such as "scrap, rework, or repair"?
• Internal Failure Costs
In the service-system design matrix, a face-to-face total customization service encounter is expected to have which of the following?
• Low efficiency • Ex.) teller vs. phone app. Teller is not as efficient.
Which company is mentioned in the text as a pioneering of the production line approach to delivering on-site service?
• McDonald's, automation capability
Which of the following refers to the "physical presence" of the customer in a "service system"?
• One-on-one customer contact, face-to-face interaction.
PERT is an abbreviation for which of the following methodologies?
• Program Evaluation and Review Technique
In monitoring process quality we might use which of the following statistics?
• Range (highest value-lowest value), standard deviation, and median
Assume a fixed cost for a process of $XX. The variable cost to produce each unit of product is $XX, and the selling price for the finished product is $XX. Which of the following is the number of units that has to be produced and sold to break-even?
• Revenue= Fixed Costs + Variable Costs • Units= revenue/price per unit
Assume a fixed cost for a process of $10. The variable cost to produce each unit of product is $5 and the selling price for the finished product is $30. Which of the following is the number of units that has to be produced and sold to break-even?
• Selling price= $30, variable cost= $5, fixed cost= $10 • $30x= $5x + $10 • $25x= $10, 10/25= x
Which of the following is a major factor that distinguishes "service design and development" from "manufacturing design and development"?
• Service is the output of developing the "product", one in the same, cannot distinguish.
Which of the following is a characteristic that can be used to "guide the design of service systems"?
• Services cannot be "inventoried".
For an activity in a CPM analysis the Early Finish time is XX and the Late Finish time is XX. Which of the following statements is true?
• The activity is on the critical path if they are the same, no slack time
Quality control charts usually have a central line and upper and lower control limit lines. Which of the following is "NOT" a reason that the process being monitored with the chart should be investigated?
• There is a change in raw materials or operators. o Outside the limits o Erratic behavior o Everything is one sided o Trend (5 point in any one direction)
With which of the following should we use an "X-bar" chart based on sample means to monitor process quality?
• Tire pressures in an auto assembly plant o D and C Charts= count data o X and R, Tire Pressure= raw data
A simple project listing of five activities and their respective time estimates are presented below:
• Using CPM, which activities make up the critical path? • Longest Time write letters like BABDE • Activity, Predecessor, Time
Which of the following is considered a High-Contact Service Operation?
• face-to-face (Dentist Office), NOT Facebook or amazon, must be a physical contact with customer.