Exam 19: Statistical Applications in Quality Management

The SS method establishes ways to eliminate unnecessary housekeeping aspects of a work environment.

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,based on the R chart,it appears that the process is out of control.

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,an R chart is to be constructed for the time required to register.One way to create the lower control limit involves multiplying the mean of the sample ranges by D₃.For this data set,the value of D₃ is .

The SS method establishes ways to organize necessary housekeeping aspects of a work environment.

Quick Changeover Techniques is among the tools of Lean Six Sigma.

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 lower control limit for this R chart?

SCENARIO 19-2 A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent.The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic. -Referring to Scenario 19-2,which expression best characterizes the p 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 limit 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 19-5 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,construct a p control chart for these data.

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 limit for the critical-to-quality variable should be 10 and 30 seconds,respectively. -Referring to Scenario 19-4,suppose the supervisor constructs an x̄ chart to see if the process is in-control.What is the center line of the chart?

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

SCENARIO 19-10 Below is the number of defective items from a production line over twenty consecutive morning shifts. -Referring to Scenario 19-10,a c chart is to be constructed for the number of defective items.The lower control limits is .

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.The lower control limit for this data set is .

SCENARIO 19-1 A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day.The owner decides to record the number of papers delivered on time for a 10-day period for one of the delivery boys and construct a p chart to see whether the percentage is too erratic. -Referring to Scenario 19-1,what is the numerical value of the lower control limit for the p chart?

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,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 .

TPM establishes ways to eliminate unnecessary housekeeping aspects of a work environment.

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

The smaller the capability index,the more capable a process is of meeting customer requirements.

SCENARIO 19-2 A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent.The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic. -Referring to Scenario 19-2,what is the numerical value of the lower control limit for the p chart?