CPS Advanced Techniques & Methods 3 — Questions and Answers
Question 1: What is the primary purpose of a Multi-Vari chart in process analysis?
- To plot defect counts over time
- To visualize the relative contribution of different sources of variation (Correct answer)
- To compare two measurement systems
- To detect autocorrelation in time-series data
Correct answer: To visualize the relative contribution of different sources of variation
A Multi-Vari chart simultaneously displays positional, cyclical, and temporal variation to identify the dominant source of process variation.
Question 2: In reliability engineering, what does MTTF measure?
- Mean Time To Failure for non-repairable items (Correct answer)
- Maximum Tolerance To Fatigue
- Mean Time To Fix for repairable systems
- Minimum Threshold of Functional output
Correct answer: Mean Time To Failure for non-repairable items
MTTF (Mean Time To Failure) is the average time a non-repairable item operates before its first — and only — failure.
Question 3: Which technique is used to systematically identify all potential failure modes of a system before it is deployed?
- SIPOC
- FMEA (Correct answer)
- QFD
- VSM
Correct answer: FMEA
Failure Mode and Effects Analysis (FMEA) proactively identifies potential failure modes, their effects, and risk priority numbers to guide mitigation.
Question 4: What does 'andon' refer to in a lean manufacturing environment?
- A poka-yoke mechanism on assembly tooling
- A visual alert system that signals abnormal conditions to stop production (Correct answer)
- A kanban card for triggering material replenishment
- A daily team meeting at the production floor
Correct answer: A visual alert system that signals abnormal conditions to stop production
Andon is a visual signal (light or board) that alerts operators and supervisors to quality or production problems, enabling rapid response.
Question 5: When conducting a gauge R&R study, what does the 'reproducibility' component measure?
- Variation due to the measurement instrument itself
- Variation when different appraisers measure the same part (Correct answer)
- Variation between different parts in the study
- Variation due to environmental conditions
Correct answer: Variation when different appraisers measure the same part
Reproducibility quantifies the variation introduced when different operators use the same gauge to measure the same parts.
Question 6: In the Theory of Constraints (TOC), what is the step that follows 'exploit the constraint'?
- Identify the constraint
- Subordinate everything else to the constraint (Correct answer)
- Elevate the constraint
- Find a new constraint
Correct answer: Subordinate everything else to the constraint
After exploiting the constraint to its maximum capacity, TOC requires subordinating all non-constraints to support the constraint's throughput.
Question 7: What is the key advantage of using Bayesian inference over classical hypothesis testing in process improvement?
- It always requires smaller sample sizes
- It incorporates prior knowledge and provides probability distributions for parameters (Correct answer)
- It eliminates the need for control charts
- It is not affected by measurement system error
Correct answer: It incorporates prior knowledge and provides probability distributions for parameters
Bayesian methods combine prior information with observed data to produce posterior distributions, offering richer inference than binary reject/fail-to-reject decisions.
CPS Advanced Techniques & Methods 3
What is the primary purpose of a Multi-Vari chart in process analysis?