Exam 13: Supplement: Statistical Quality Control and Six Sigma Quality Management

An airline wants to monitor the performance of their baggage handling crew on the daily flight from Syracuse to Boston that is always filled to its 140 passenger capacity. They track the number of passengers that lose bags each flight for a two week period. The data are displayed in the following table. -Calculate " , the mean percent defective for all samples collected.

Zimken Bearings has been making a special type of bearing with a diameter of 0.8 inches and a standard deviation of 0.004 inches. A new customer has a design requirement for a bearing with a diameter specification of 0.79 inches and a tolerance of ± 0.02 inches. Determine the C_pk.

A pizza delivery service wants to track their delivery times. They take eight samples of four deliveries and record the following data. What are the upper and lower control limits of their chart?

A drive-in restaurant is running a new promotion, the "Route 44," named after an interstate that runs through their primary market area. The drink is promoted as 44 ounces of pure carbonated pleasure but the regional manager, being somewhat of a quality expert, wants to make sure that the company's drink process can deliver 44 ounces. She decides statistical quality control is the best way to monitor their process. For ten consecutive days she purchases five Route 44 drinks from franchise locations on her way to headquarters and turns them over to the testing lab for volume analysis. The data appear in the table, all amounts are in fluid ounces as measured by the testing lab. The regional manager is more concerned about the consistency of the process, figuring that if the cups are filled, the amount will be close enough for beverage work. -The LCL for the three sigma R chart for the process is approximately:

Sample means and ranges were obtained for five samples of 10 units per sample from a production process. Assume the process was considered to be in control during the period these samples were collected. The results are as follows: -What is the central line of the X bar chart for this process?

Forty samples of 100 are taken, with the total number of defective units being 150. -Calculate the lower control limit for the chart, using z = 3.

Boyd Tooling has an automated drilling machine and the owners want to determine the equipment's capability for machining a part's diameter to a specification of 0.350 ± 0.004 inches. After a trial run period, the lathe produced a sample mean of 0.351 inches, with a standard deviation of 0.0009 inch. Calculate the C_pk for this drilling machine.

Over a 10-day period, an outdoor light post manufacturer has counted the number of units not meeting design specifications. The findings are shown below. -Calculate the upper control limits for the C chart using z = 3

An airline wants to monitor the performance of their baggage handling crew on the daily flight from Syracuse to Boston that is always filled to its 140 passenger capacity. They track the number of passengers that lose bags each flight for a two week period. The data are displayed in the following table. -Calculate the lower control limit for the chart, using z = 3.

Romeo and Juliet make and sell cookies for their online business, Heartbreak Abode. They want to track quality, so they decide to calculate their defects per million opportunities, or DPMO, each month. For each box of cookies they sell, there can be 7 possible defects or customer complaints. During the last month, Heartbreak filled 725 orders. They received 49 complaints. -To achieve a defects per million opportunities (DPMO) value of 233, what would be the number of complaints?

A drive-in restaurant is running a new promotion, the "Route 44," named after an interstate that runs through their primary market area. The drink is promoted as 44 ounces of pure carbonated pleasure but the regional manager, being somewhat of a quality expert, wants to make sure that the company's drink process can deliver 44 ounces. She decides statistical quality control is the best way to monitor their process. For ten consecutive days she purchases five Route 44 drinks from franchise locations on her way to headquarters and turns them over to the testing lab for volume analysis. The data appear in the table, all amounts are in fluid ounces as measured by the testing lab. Since the regional manager is somewhat of a quality expert, she needs your help in formulating a control chart that will monitor the process performance to target. -The UCL for the three sigma X bar chart for the process is approximately:

A company currently produced 750,000 units, with a total defect level of 6,300. Each unit has a potential of 300 defects. -When the sigma level is 2, the percentage of defect-free output is _______.

Use the information contained in this chart to determine your answer. Twenty samples of size 8 were taken from a stable process. From past studies of the process, you know that the overall mean is 42.5 and that the average of the samples range is 2.0. -The UCL for the three sigma X bar chart for the process is approximately (for a sample size of 8, A₂ = 0.373):

A product has 6 parts, the company has produced 2,750 units, and so far, they have had 3 customer complaints about quality. -What will be your best choice for the company's Six Sigma operating level?

Fifteen samples of size 10 are taken from a stable process. The average of the sample means is 32.8, and the average range of the samples is 1.5. Use the information contained in the chart below (Table 13s.1): -The LCL for the three sigma R chart for the process is approximately (for a sample size of 10, D₃ = 1.777, D₄ = 0.223):

Number of defects = 750; opportunities for a defect to occur = 5; number of units = 16,000 -Calculate the defects per million opportunities, DPMO.

A company currently produced 750,000 units, with a total defect level of 6,300. Each unit has a potential of 300 defects. -When defects per million opportunities (DPMO) is 22.750, the sigma level is _______.