Föreläsningar del 12 Flashcards
Flashcard 1: Q: What is the primary goal of quality control?
A: The goal of quality control is to ensure that a good or service conforms to specifications and meets customer requirements by monitoring and measuring processes, and making necessary adjustments to maintain performance.
Flashcard 2: Q: What are the key components of a quality control system?
A: The key components are:
* Performance standard or goal.
* Means of measuring actual performance.
* Comparison of actual performance with the standard for corrective action.
Flashcard 3: Q: What are the common quality control practices?
A: Common practices include:
* Supplier certification and management.
* In-process control.
* Finished-goods control.
Flashcard 4: Q: How do you construct a confidence interval for the true mean assuming normal distribution?
A: By using the standardized normal distribution variable z and constructing a confidence interval with z-values found in the standard normal distribution table.
Flashcard 5: Q: What does an acceptance test with a qualitative variable focus on?
A: It focuses on monitoring the proportion of nonconforming or defective units in a sample, assuming the sample size meets the requirements for normal distribution: NP ≥ 5 and n(1-p) ≥ 5.
Flashcard 6: Q: What does it mean if random samples remain within the UCL - LCL interval?
A: It means the process is considered to be functioning normally, as long as the random samples stay within the control limits.
Flashcard 7: Q: What is the primary concern when working with P charts in process control?
A: The primary concern is the Upper Control Limit (UCL), not the Lower Control Limit (LCL), when analyzing the number of defects.
Flashcard 8: Q: What does it indicate if the assumption of randomness doesn’t hold in a production process?
A: It indicates that something other than randomness is causing deviations, and the process may need to be adjusted.
Flashcard 10: Q: How do series and parallel systems differ in terms of reliability?
A: In series systems, all components must work for the system to function, and reliability decreases with more components. In parallel systems, at least one component must work, and reliability increases with more components.
Flashcard 11: Q: How do reliability and process control relate in series and parallel systems?
A: In series production systems, control limits for individual components might need to be tightened to safeguard the quality of the entire system. In contrast, if quality is hard to achieve in individual components, parallel systems may be used to improve reliability.
What are the Rules of thumb for identifying a shift in a process?
- 8 points in a row are above or below the centerline.
- 10 of 11 Consecutive points are above or below the centerline.
- 12 of 14 consecutive points are above or below the center line.
- 2 of 3 Consecutive points are in the outer one-third region between the center line and one of the control limits.
- 4 of 5 consecutive points are in the outer two-thirds region between the center line and one of the control limits.
Q: What are the key elements of a decision problem?
A: A decision problem is characterized by decision alternatives, states of nature, and resulting payoffs.
Q: What should the states of nature in a decision problem be?
A: States of nature should be mutually exclusive and collectively exhaustive.
Q: What is the purpose of an influence diagram?
A: An influence diagram is a graphical device used to show the relationships among decisions, chance events, and consequences.
Q: What do the shapes represent in an influence diagram?
A: Squares/rectangles represent decision nodes, circles/ovals represent chance nodes, and diamonds represent consequence nodes.
