Exam 19: Statistical Applications in Quality Management Online

SCENARIO 19-8 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 Scenario 19-8, based on the R chart, it appears that the process is out of control.

Common causes of variation are correctable without modifying the system.

SCENARIO 19-4 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 limits for the critical-to-quality variable should be 10 and 30 seconds, respectively. -Referring to Scenario 19-4, suppose the supervisor constructs an R chart to see if the variability in collection times is in-control.This R chart is characterized by which of the following?

SCENARIO 19-5 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 Scenario 19-5, a p control chart is to be made for these data.The center line of the control chart is __________.

Which of the following is not part of the Shewhart-Deming cycle?

SCENARIO 19-6 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 Scenario 19-6, construct a p control chart for these data.

The control limits are based on the standard deviation of the process.

Special or assignable causes of variation are signaled by individual fluctuations or patterns in the data.

SMED focuses on preventing the causes of defects.

It is not possible for the chart to be out-of-control when the R chart is in control.

SCENARIO 19-4 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 limits for the critical-to-quality variable should be 10 and 30 seconds, respectively. -Referring to Scenario 19-4, suppose the supervisor constructs an chart to see if the process is in-control.What are the lower and upper control limits of this chart?

SCENARIO 19-4 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 limits for the critical-to-quality variable should be 10 and 30 seconds, respectively. -Referring to Scenario 19-4, 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?

SCENARIO 19-7 A supplier of silicone sheets for producers of computer chips wants to evaluate her manufacturing process.She takes samples of size 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. She also decides that the upper specification limit is 10 blemishes. -Referring to Scenario 19-7, an R chart is to be constructed for the number of blemishes. One way to create the upper control limit involves multiplying the mean of the sample ranges by For this data set, the value of is ________.

An in-control process must be achieved before being able to estimate process capability.

TPM establishes ways to clean and maintain the necessary housekeeping aspects of a work environment.

SCENARIO 19-4 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 limits for the critical-to-quality variable should be 10 and 30 seconds, respectively. -Referring to Scenario 19-4, what is the value of the C index?

SCENARIO 19-3 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 Scenario 19-3, suppose the analyst constructs an chart to see if the production process is in-control.What is the center line for this chart?

SCENARIO 19-3 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 Scenario 19-3, 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?

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

SCENARIO 19-9 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 Scenario 19-9, construct an R chart for the time required to register.