Statistical Quality Control
Assignment: Please read the material (Fundamentals of Quality Control and Improvement) and lectures, use the book to answers all questions as followed.
Acceptance SamplingQuestion 1 (Chapter 10, 10-2):
Distinguish between producers risk and consumers risk. In this context, explain the terms acceptable quality level and limiting quality level. Discuss instances for which one type of risk might be more important than the other.
Question 2 (Chapter 10, 10-4):
Discuss the relative advantages and disadvantages of single, double, and multiple sampling plans.
Question 3 (Chapter 10, 10-15):
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 protection offered by the plan at these quality levels.
ReliabilityQuestion 4 (Chapter 11, 11-3):
Explain procedures that might improve the reliability of a system. How would you increase the availability of a system? Distinguish between a system with components in parallel and another with standby components.
Question 5 (Chapter 11, 11-4):
Distinguish between failure-, time-terminated, and sequential tests for reliability and life testing.
Question 6 (Chapter 11, 11-5):
A transistor has an exponential time-to-failure distribution with a constant failure rate of 0.00006/hour. Find the reliability of the transistor after 4000 hours of operation. What is the mean time to failure? If the repair rate is 0.004/hour, find the availability.
Question 7 (Chapter 11, 11-12):
Consider the seven-component system shown in the figure below. 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 system reliability by modifying any two components, how would you proceed?