Reliability and Quality Control (INDSE5A) — DU B.Sc. (Hons) Instrumentation Previous Year Question Papers

(c) A company manufactures a critical electronic component with a specified MTTF of 10,000 hours and an MTTR of 2 hours. Calculate the availability of the component and discuss how this information can influence production and maintenance strategies. (6) . Control (DSE) (b) Explain the importance of sample size and sampling frequency in the construction of control charts. (3) (c) Explain the terms Acceptable Quality Level and Lot Tolerance Percent Defective. (3) (d) Discuss how reliability can be improved in electronic systems through design choices. (3) (e) What is a Pareto Diagram, and how is it used in quality improvement? (3) (f) Briefly explain Juran's approach to quality and its significance in management. (3) 2. (a) A grinding machine has a specification of 40 mm + 0.1 mm. Over 5 days, a sample of 6 parts was measured daily, yielding the following diameters : (b) Compare and contrast the control charts for attributes: p-chart and np-chart. Describe the scenarios where each type would be appropriate and explain the difference in their construction and interpretation. (6) (c) Explain the purpose and methods of evaluating quality control in an organization. Describe key performance indicators and metrics that can be used to assess the effectiveness of quality control practices. (6) 7. (a) For a single sampling plan with N=20,000, n=200, and c=3, if the probability of acceptance for lots with 2% defective items is 0.870, determine the AOQ value for these lots. (6) (b) Define Kaizen and explain its role in continuous improvement. Describe how Kaizen principles are applied in a workplace and give examples of small, incremental changes that can lead to significant improvements in quality. (6) (b) Define the failure density function in the context of reliability engineering. Explain how it is used to determine the probability of failure over time, and illustrate its relation to the reliability function with a diagram. (6) (c) Consider a scenario in a manufacturing industry where quality issues are affecting customer satisfaction. Choose one quality management approach and describe how you would apply it to address and resolve the quality issues. (6) 6. (a) In a hydraulic control system, the connecting linkage has a reliability factor of 0.98. The pressure sensor actuates the linkage has a reliability factor of 0.92. The pressure sensor which actuates the valve has a reliability factor of 0.90. Assume that all the three elements namely; the actuator, the linkage and the hydraulic valve are connected in series with independent reliability factors. What is the reliability of the control system. (6) Construct the X bar and R chart and find out the process capability for the machine. State whether the process is in control or not. (Assume: d,=2.326, (b) A company implementing Six Sigma noticed a gradual improvement in quality but an initial increase in costs. Explain how the Value of