Exam 18: Statistical Applications in Quality Management

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 analyst constructs an R chart to see if the variability in production times is in-control.What is the center line of this R chart?

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 center line of this R chart is located at ________.

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 chart is to be used for the weight.The center line of this chart is located at ________.

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 analyst constructs an chart to see if the production process is in-control.What is the upper control limit (UCL)for this chart?

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 chart is to be used for the weight.One way to obtain the control limits is to take the grand mean and add and subtract the product of A₂ times the mean of the sample ranges.For this data set,the value of A₂ is ________.

TABLE 18-8 Recently,a university switched to a new type of computer-based registration.The registrar is concerned with the amount of time students are spending on the computer registering under the new system.She decides to randomly select 8 students on each of the 12 days of the registration and determine the time each spends on the computer registering.The range,mean,and standard deviation of the times required to register are in the table that follows. -Referring to Table 18-8,an chart is to be used for the time required to register.One way to obtain the control limits is to take the grand mean and add and subtract the product of A₂ times the mean of the sample ranges.For this data set,the value of A₂ 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 analyst constructs an R chart to see if the variability in production times is in-control.What is the lower control limit for this R chart?

One of the morals of the red bead experiment is

The Shewhart-Deming cycle plays an important role in which of the following Deming's 14 points for management?

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.The lower control limit for this data set 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. -True or False: Referring to Table 18-6,the process seems to be in control.

True or False: The C_pk is a one-sided specification limit.

TABLE 18-8 Recently,a university switched to a new type of computer-based registration.The registrar is concerned with the amount of time students are spending on the computer registering under the new system.She decides to randomly select 8 students on each of the 12 days of the registration and determine the time each spends on the computer registering.The range,mean,and standard deviation of the times required to register are in the table that follows. -Referring to Table 18-8,an R chart is to be constructed for the time required to register.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 18-5 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. -Referring to Table 18-5,a p control chart is to be made for these data.The center line of the control chart is ________.

True or False: The CPL and CPU indexes are used to measure process' actual performance rather than its potential.

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 analyst constructs an R chart to see if the variability in production times is in-control.What is the upper control limit for this R 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: It is not possible for the chart to be out-of-control when the R chart is in control.

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 R chart to see if the variability in collection times is in-control.What is the center line of this R chart?

Determining the root causes of why defects can occur along with the variables in the process that cause these defects to occur involves which part of the DMAIC process?

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 analyst constructs an R chart to see if the variability in production times is in-control.The R chart is characterized by which of the following?