Exam 18: Statistical Applications in Quality Management

TABLE 18-6 The maker of a packaged candy wants to evaluate the quality of her production process.On each of 16 consecutive days,she samples 600 bags of candy and determines the number in each day's sample that she considers to be of poor quality.The data that she developed follow. -Referring to Table 18-6,a p control chart is to be constructed for these data.The estimate of the standard error of the sample proportion is ________.

TABLE 18-3 A quality control analyst for a light bulb manufacturer is concerned that the time it takes to produce a batch of light bulbs is too erratic.Accordingly,the analyst randomly surveys 10 production periods each day for 14 days and records the sample mean and range for each day. -Referring to Table 18-3,suppose the sample mean and range data were based on 11 observations per day instead of 10.How would this change affect the lower and upper control limits of the R chart?

TABLE 18-6 The maker of a packaged candy wants to evaluate the quality of her production process.On each of 16 consecutive days,she samples 600 bags of candy and determines the number in each day's sample that she considers to be of poor quality.The data that she developed follow. -Referring to Table 18-6,the estimate of the proportion of poor quality bags of candy is ________.

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -True or False: One of the morals of the red bead experiment is that variation is part of any process.

TABLE 18-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. -Referring to Table 18-9,estimate the percentage of the cans whose weight is inside the specification limit.

TABLE 18-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. -True or False: Referring to Table 18-9,based on the R chart,it appears that the process is out of control.

TABLE 18-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. -Referring to Table 18-9,an R chart is to be constructed for the weight.One way to create the upper control limit involves multiplying the mean of the sample ranges by D₄.For this data set,the value of D₄ is ________.

TABLE 18-6 The maker of a packaged candy wants to evaluate the quality of her production process.On each of 16 consecutive days,she samples 600 bags of candy and determines the number in each day's sample that she considers to be of poor quality.The data that she developed follow. -Referring to Table 18-6,a p control chart is to be constructed for these data.The center line for the chart should be located at ________.

TABLE 18-5 A manufacturer of computer disks took samples of 240 disks on 15 consecutive days.The number of disks with bad sectors was determined for each of these samples.The results are in the table that follows. -True or False: Referring to Table 18-5,the process seems to be in control.

True or False: Referring to Table 18-8,based on the chart,it appears that the process is in control.

TABLE 18-10 Below is the number of defective items from a production line over twenty consecutive morning shifts. -Referring to Table 18-10,a c chart is to be constructed for the number of defective items.The lower control limits is ________.

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -True or False: Special or assignable causes of variation are signaled by individual fluctuations or patterns in the data.

TABLE 18-7 A supplier of silicone sheets for producers of computer chips wants to evaluate her manufacturing process.She takes sample sizes of 5 from each day's output and counts the number of blemishes on each silicone sheet.The results from 20 days of such evaluations are presented below. Sheet Day 1 2 3 4 5 Mean Range 1 8 10 14 6 5 8.6 9 2 8 13 6 6 10 8.6 7 3 10 12 7 7 9 9.0 5 4 5 9 12 7 10 8.6 7 5 8 3 8 9 10 7.6 7 6 9 7 9 6 9 8.0 3 7 10 10 5 7 6 7.6 5 8 10 9 10 6 5 8.0 5 9 6 10 6 9 9 8.0 4 10 6 9 8 6 8 7.4 3 11 8 5 6 10 10 7.8 5 12 6 4 7 7 12 7.2 8 13 7 5 7 6 9 6.8 4 14 5 8 8 7 6 6.8 3 15 7 12 10 6 10 9.0 6 16 7 11 4 7 8 7.4 7 17 8 4 5 4 7 5.6 4 18 11 4 11 11 10 9.4 7 19 6 10 6 10 10 8.4 4 20 6 12 12 6 8 8.8 6 She also decides that the upper specification limit is 10 blemishes. -Referring to Table 18-7,an R chart is to be constructed for the number of blemishes.The upper control limit for this data set is ________.

Variation signaled by individual fluctuations or patterns in the data is called

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -Referring to Table 18-4,suppose the supervisor constructs an chart to see if the process is in-control.What is the center line of the chart?

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -True or False: The R chart is a control chart used to monitor a process mean.

TABLE 18-10 Below is the number of defective items from a production line over twenty consecutive morning shifts. -Referring to Table 18-10,a c chart is to be constructed for the number of defective items.The upper control limits is ________.

Developing operational definitions for each critical-to-quality characteristic involves which part of the DMAIC process?

TABLE 18-9 The manufacturer of canned food constructed control charts and analyzed several quality characteristics.One characteristic of interest is the weight of the filled cans.The lower specification limit for weight is 2.95 pounds.The table below provides the range and mean of the weights of five cans tested every fifteen minutes during a day's production. -Referring to Table 18-9,construct an R chart for the time required to register.

TABLE 18-4 A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds)is too erratic and adversely affects expected profits.The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours.The sample mean and range for each hour are listed below. She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -Referring to Table 18-4,suppose the sample mean and range data were based on 6 observations per hour instead of 5.How would this change affect the lower and upper control limits of an R chart?