Suppose that desirable producer’s risk is 3% and consumer’s risk is 6%. Which of the plans described in Exercises 10-15 and 10-16 are preferable? Discuss your choice.
> State the null and alternative hypotheses in the following situations by defining the parameters used. Also, state any assumptions that you need to make to conduct the test: (a) The Postal Service wishes to prove that the mean delivery time for packages
> A standby system has a basic unit with four standby components. The time to failure of each component has an exponential distribution with a failure rate of 0.008/hour. For a 400-hour operation period, find the reliability of the standby system. What is
> Consider the seven-component system shown in Figure 11-14. Assume that the time to failure for each component has an exponential distribution. The failure rates are as follows: λA = 0.0005/hour, λB= 0.0005/hour, λC=
> Consider the seven-component system shown in Figure 11-14. The reliabilities of the components are as follows: RA = 0.96, RB= 0.92, RC=0.94, RD = 0.89, RE = 0.95, RF=0.88, RG =0.90. Find the reliability of the system. If you had a choice of improving sys
> Refer to Exercise 11-10. Each component has a time to failure that is exponentially distributed, with a mean time to failure of 3000 hours. Find the reliability of the subassembly for 2500 hours of operation. What is the mean time to failure of the subas
> Four components A, B, C, and D are placed in parallel to make a subassembly in a circuit board. The reliabilities of A, B, C, and D are 0.93, 0.88, 0.95, and 0.92, respectively. Find the reliability of the subassembly.
> A cereal manufacturer who claims to meet certain mineral and vitamin requirements has a minimum specification of 25% for the iron content. The standard deviation of the iron content is estimated to be 3%. It is preferred to accept batches that are 1.5% n
> The thickness of silicon wafers is an important characteristic in microelectronic circuits. The upper specification limit for the thickness is 0.015 mm. It is estimated that the standard deviation of the thickness of wafers is 0. 0014mm.We wish to accept
> A dairy has to control the amount of butterfat in its low-fat milk. The upper specification limit of the fat content is 4 g for 4-L containers. The standard deviation of the fat content for these containers is estimated to be 0.5 g. It is desired to acce
> Unleaded gasoline must meet certain federal standards. The octane number for a particular brand must be at least 89. The standard deviation of the octane number is estimated to be 4. It is preferred to accept shipments for which the average octane number
> Refer to Exercise 10-52 regarding the proportion of carbon monoxide in exhaust gases, which has an upper specification limit of 0.30. Ifthe average carbon monoxide content is 1 standard deviation below the upper specification limit, the devices should be
> Distinguish between the use of the mean, median, and mode in quality control applications. When do you prefer to use the trimmed mean?
> The proportion of carbon monoxide in exhaust gases has an upper specification limit of 0.30. Emission control devices are being tested to meet such requirements. We wish that devices with an average carbon monoxide content of 0.15 or less be accepted 95%
> The length of connector pins has an upper specification limit of 45 mm and a lower specification limit of 40 mm. It is desirable that lots with a mean such that 8% of the product is nonconforming, either above the upper specification limit or below the l
> The tensile strength of an alloy has double specification limits. If the process average tensile strength is below 800 kg/cm2 or above 1200 kg/cm2, it is desired to accept such lots with a probability of 0.08. For lots with a process average of 1000 kg/c
> The lower specification limit for the breaking strength of yarns is 25 g. The distribution of the breaking strength of yarns is normal with a variance of 6. It is desirable that lots with a mean such that 3% of the product is nonconforming be accepted 94
> The upper specification limit for the resistance of coils is 30 Ω. The distribution of coil resistance is known to be normal with a standard deviation of 5 Ω. It is preferred to reject batches that have a mean of 2.3 standard deviations below the upper s
> In the construction industry, the initial inspection of tie beams is estimated to cost $0.20 per unit. If, however, a nonconforming beam is allowed for construction purposes, the unit cost of rectifying and replacing it is $50. What inspection policy sho
> Refer to Exercise 10-44. lf the monthly production is 2000 units, what is the average savings in total inspection costs when using Deming’s kp rule as opposed to 100% inspection? Data from Exercise 10-44: In Exercise 10-43, if the initial inspection cos
> Refer to Exercise 10-43, Suppose that the monthly production is 3000 units. What is the average savings in total inspection costs per month when using the policy found from Deming’s kp rule as opposed to no inspection? Data from Exercise 10-43: The init
> In Exercise 10-43, if the initial inspection costs of the transmission systems are $1.00 per unit, what inspection policy should be followed using Deming’s kp rule? Data from Exercise 10-43: The initial inspection of transmission systems in automobiles
> The initial inspection of transmission systems in automobiles is estimated to cost $0.50 per unit. If a nonconforming transmission is allowed in the assembly, the unit cost to eventually disassemble and replace it is $225. The estimated proportion noncon
> Explain the different types of measurement scales and give examples in the following situations: (a) Gallons of water to put out a fire by the fire department (b) Response time of an ambulance (c) Test score in an examination (d) Customer product prefere
> A sequential sampling plan is to be used. It is desirable to have a producer’s risk of 0.05 at AQL= 0.008 and a consumer’s risk of 0.07 at LQL= 0.082. Determine the equations for the acceptance and rejection lines. What is the first opportunity to reject
> The equations for the acceptance and rejection lines for a sequential sampling plan are given as follows: What is the first opportunity to reject? What is the first opportunity to accept?
> A chain sampling plan is used with a sample size of 5 and a parameter i of 3. If lots have a proportion nonconforming of 0.06, find the probability of accepting such lots.
> Find a Dodge–Romig single sampling plan if the lot size is 600, the process average is 1.4% nonconforming, and AOQL=3%. Determine and interpret the LQL for the plan.
> Find a Dodge–Romig single sampling plan if the lot size is 2200 and LQL = 5.0%. Determine and interpret the AOQL for the plan.
> Find a Dodge–Romig single sampling plan if the lot size is 900, LQL= 5% nonconforming, and the process average is 0.8% nonconforming. What is the AOQL for the plan? Interpret it.
> Refer to Exercise 10-33. Find the sampling plan if it is desired to accept batches that are 5% nonconforming with a probability of 0.5. Data from Exercise 10-33: A double sampling plan is desired that has a producer’s risk of 0.05 at AQL =1.8% nonconfor
> Refer to Exercise 10-33. Find the double sampling plan if the second sample is to be twice as large as the first sample and the consumer’s stipulation is to be satisfied exactly. Data from Exercise 10-33: A double sampling plan is desired that has a pro
> It is desired to accept lots that are 9.5% nonconforming with a probability of 0.10 and to accept lots that are 2.3% nonconforming with a probability of 0.95. Find a double sampling plan for a lot size of 2000 if the second sample is to be twice as large
> A double sampling plan is desired that has a producer’s risk of 0.05 at AQL =1.8% nonconforming and a consumer’s risk of 0.10 at LQL =8.5% nonconforming. The lot size is 1500, and the sample sizes are assumed to be equal. Find the sampling plan if the pr
> Explain the difference between accuracy and precision of measurements. How do you control for accuracy? What can you do about precision?
> Refer to Exercise 10-30. What is the average sample number of incoming lots that are 2% nonconforming? What is the average total inspection for this quality level of 2% nonconforming? Data from Exercise 10-30: Consider a double sampling plan given by th
> Consider a double sampling plan given by the following parameters: N =2200, n1= 60, c1= 0, r1=5, n2= 100, c2= 6, r2=7. Find the probability of accepting lots that are 3% nonconforming. What is the probability of accepting a lot on the first sample? What
> Consider a double sampling plan given by the following parameters: N =1200, n1= 50, c1= 1, r1=4, n2= 110, c2= 5, r2=6. Find the probability of accepting lots that are 4% nonconforming. What is the probability of rejecting a lot on the first sample?
> A sampling plan is desired to have a producer’s risk of 0.05 at AQL =2.0% nonconforming and a consumer’s risk of 0.10 at LQL =7% nonconforming. Find the single sampling plan with the largest sample size. Find the single sampling plan with the smallest sa
> A sampling plan is desired to have a producer’s risk of 0.05 at AQL =1.3% nonconforming and a consumer’s risk of 0.10 at LQL= 7.1% nonconforming. Find the single sampling plan that meets the producer’s stipulation and comes as close as possible to meetin
> A sampling plan is desired to have a producer’s risk of 0.05 at AQL =0.9% and a consumer’s risk of 0.10 at LQL =6.5% nonconforming. Find the single sampling plan that meets the consumer’s stipulation and comes as close as possible to meeting the producer
> Determine single sampling plans that will accept lots that are 0.8% nonconforming with a probability of 0.96. Use acceptance numbers of 1, 3, and 4. If we desire batches that are 5% nonconforming to be accepted with a probability of no more than 0.04, wh
> Determine the single sampling plans that will accept lots that are 6% nonconforming 12% of the time. Use acceptance numbers of 1, 2, and 4. From a producer’s point of view, which of these plans would you choose?
> Determine the single sampling plans that will reject lots that are 1.3% nonconforming 8% of the time. Use acceptance numbers of 1, 3, and 5. From a consumer’s point of view, which of these three plans would you choose?
> A manufacturer is considering replacement of an existing machine that performs an operation on a part. The variable costs are $0.38 per piece on the existing machine and $0.05 per piece on the new machine. The cost of the new machine is $40,000, while th
> Find an expression for the probability of the union of three events that are mutually independent of each other.
> For the double sampling plan N= 2200, n1= 60, c1=1, r1=5, n2= 120, c2= 4, r2=5, construct the ASN curve. Within what range of proportion nonconforming values would you prefer the stated double sampling plan over a single sampling plan with n= 85, c= 2 in
> For the double sampling plan N = 2000, n1=80, c1= 1, r1=3, n2= 100, c2=2, r2= 3, construct and interpret the ASN curve. Suppose that process average nonconforming rate is 1.5%. Would you prefer the stated double sampling plan or a single sampling plan wi
> Construct the ATI curve for the sampling plan N = 1200, n= 50, c =1. Suppose that the process average nonconforming rate is 3%. Explain the value of ATI for that level of non-conformance.
> For the sampling plan N= 1500, n= 150, c= 3, construct the average outgoing quality curve. What is the AOQL? Interpret it.
> Consider Exercise 10-15. Answer the same questions for the sampling plan N= 1500, n=200, c=3.Discussthe degree of protection of this plan compared to that in Exercise 10-15. Data from Exercise 10-15: Consider a single sampling plan with a lot size of 15
> Consider a single sampling plan with a lot size of 1500, sample size of 150, and acceptance number of 3. Construct the OC curve. If the acceptable quality level is 0.05% nonconforming and the limiting quality level is 6% nonconforming, describe the prote
> Refer to Exercise 9-49 on the laboratory turnaround time data. The facility wanted to compare its updated performance to another metropolitan facility serving the needs of similar patients. The other facility had a mean turnaround time of 35 minutes with
> Refer to Exercise 9-48. The quality improvement team, after a thorough study of the existing processes, recommended some procedural changes. Data collected after the changes yielded a mean turnaround time of 40 minutes with a standard deviation of 10 min
> Customers arrive at a department store randomly and independently. (a) What is an appropriate distribution for modelling the number of customers that arrive in a 2-hour period? (b) Under what situations might the stated assumptions not hold? (c) What inf
> The senior management in an urban bank is committed to improving its services. Discuss the specifics of quality of design, conformance, and performance in this context. Elaborate on possible basic needs, performance needs, and excitement needs of the cus
> A health care facility in a metropolitan area is interested in the efficiency of its laboratory turnaround time. Based on data collected over last year, the mean turnaround time was found to be 55 minutes with a standard deviation of 15 minutes. The faci
> Refer to Exercise 9-46. In order to boost product sales, the manager is contemplating the hiring of an additional sales staff. The added monthly cost of this hire will be $6000, but the expected monthly sales is projected to be $65,000 with a standard de
> For a marketing manager of a company, product sales in a specified market is of importance. Currently, for a brand-named product, the mean monthly sales are $50,000 with a standard deviation of $3500. Assuming normality of the distribution of monthly sal
> Refer to Exercise 9-42. The investment bank was able to identify a riskier strategy that projects a mean yield of 9.2% with a standard deviation of 2.4%. Assuming normality of distribution of yield rates, what is the lower capability index now if a targe
> Refer to Exercise 9-43 on the investment bank. Using the investment strategy that yields a mean yield of 7.0% with a standard deviation of 0.9%, what should a published goal of yield for customers be if the bank wants to be 95% sure of meeting that goal?
> Refer to Exercise 9-42. With the adoption of a slightly more conservative investment strategy, the bank forecasts a mean yield of 7.0% with a standard deviation of 0.9%. Assuming normality of distribution of yield rates, what is the lower capability inde
> An investment bank has been monitoring its return on investment for a certain category of its shareholders. Past data show a mean yield of 7.5% with a standard deviation of 1.5%. Assuming normality of distribution of yield rates, if senior management has
> Refer to Exercise 2-2. For each situation, explain what factors influence customer perception of quality and how they are to be managed. Data from Exercise 2-2: Discuss some service nonconformity and behavioural characteristics in the following areas: (
> Refer to Exercise 2-2. For each situation, discuss the ease or difficulty of measuring service quality. What are some remedial measures? Data from Exercise 2-2: Discuss some service nonconformity and behavioural characteristics in the following areas: (
> Discuss some service nonconformity and behavioural characteristics in the following areas: (a) Health care (b) Call center (c) Internal Revenue Service (d) Airline industry
> For each of the following areas, define appropriate quality characteristic(s) and parameters and indicate the hypotheses that you would test: (a) Effectiveness of a hospital in satisfying patients, employees, and shareholders (note that different hypothe
> Who is the customer in health care? Describe some of the customer’s needs.
> Consider the logistics company in Exercise 3-8. Conduct a quality function deployment analysis where the objective is to minimize delays in promised delivery dates. Data from Exercise 3-8: Consider a logistics company transporting goods on a global basi
> Consider a logistics company transporting goods on a global basis. Identify possible vision and mission statements and company strategies. Conduct a balanced scorecard analysis and indicate suggested diagnostic and strategic measures in each of the areas
> Consider the airline transportation industry. Develop a house of quality showing customer requirements and technical descriptors.
> Select an organization of your choice in the following categories. Identify the organization’s strategy. Based on these strategies, perform a balanced scorecard analysis by indicating possible diagnostic and strategic measures in each of the areas of lea
> What are the advantages of using quality function deployment? What are some key ingredients that are necessary for its success?
> Describe Motorola’s concept of six sigma quality and explain the level of nonconforming product that could be expected from such a process.
> Compare and contrast a company vision, mission, and quality policy. Discuss these concepts in the context of a hospital of your choice.
> Consider a visit to your local physician’s office for a routine procedure. Develop a flowchart for the process. What methods could be implemented to improve your satisfaction and reduce waiting time?
> You are asked to make a presentation to senior management outlining the demand for a product. Describe the data you would collect and the tools you would use to organize your presentation.
> With increased air travel, the training of air traffic controllers is vital. However, of those who enter the program, several drop out, for a variety of reasons. In the past, 70% have completed the program. A new program is being developed at significant
> What are the advantages of creating a long-term partnership with vendors?
> Consider Exercise 3-18 on the prevention of automobile accidents. However, in this exercise, consider the driver of the automobile. Construct a cause-and-effect diagram for accidents influenced by the driver. Conduct a failure model and effects criticali
> The safe operation of an automobile is dependent on several subsystems (e.g., engine, transmission, braking mechanism). Construct a cause-and-effect diagram for automobile accidents. Conduct a failure mode and effects criticality analysis and comment on
> The postal system has undertaken a quality improvement project to reduce the number of lost packages. Construct a cause-and-effect diagram and discuss possible measures that should be taken.
> Discuss the role of national and international standards in certifying vendors.
> What is the purpose of vendor certification? Describe typical phases of certification
> In a large city, the mass-transit system, currently operated by the city, needs to be overhauled with projected demand expected to increase substantially in the future. The city government is considering possible outsourcing. (a) Discuss the mission and
> The area of nanotechnology is of much importance in many phases of our lives—one particular area being development of drugs for Alzheimer’s disease. Discuss the role of benchmarking, innovation, and time-based competition in this context.
> A financial institution is considering outsourcing its information technology–related services. What are some criteria that the institution should consider? Propose a scheme to select a vendor.
> What are the various types of quality audits? Discuss each and identify the context in which they are used.
> Which type of control chart (p, np, c, u, U, or charts for highly conforming processes) is most appropriate to monitor the following situations? (a) Number of potholes in highways (b) Proportion of customers who are satisfied with the operation of the lo
> Describe the steps of benchmarking relative to a company that develops microchips. What is the role of top management in this process?
> Describe the total quality management philosophy. Choose a company and discuss how its quality culture fits this theme.
> In a chemical process, the parameters of temperature, pressure, proportion of catalyst, and pH value of the mixture influence the acceptability of the batch. The data from 20 observations are shown in Table 3-15. (a) Construct a multivariable chart. What
> Discuss the emerging role of ISO 9000 standards in the global economy.
> Is accomplishing registration to ISO 9001 standards similar to undergoing an audit process? What are the differences?
> Use a flowchart to develop an advertising campaign for a new product that you will present to top management.
> An insurance company is interested in determining whether life insurance coverage is influenced linearly by disposable income. A randomly chosen sample of size 20 produced the data shown in Table 3-14. Construct a scatterplot. What conclusions can you dr
> In a printing company, data from the previous month show the following types of errors, with the unit cost (in dollars) of rectifying each error, in Table 3-13. (a) Construct a Pareto chart and discuss the results. (b) If management has a monthly allocat
> Discuss the role of established standards and third-party auditors in quality auditing. What is the role of ISO 9000 standards in this context?
> Discuss the challenges and the contributions that could be derived from development of a health care decision support system in the current century.
> For the hardware company in Exercise 1-15, suppose that setup and testing costs are different for CPUs and monitors. Annual costs for setup and testing are $0.4 million and $0.7 million for CPUs and monitors, respectively. However, between two types of C
> What are some of the challenges faced by the health care industry in the twenty-first century?
