COM Data Analysis & Decision Making 2 — Questions and Answers
Question 1: A operations manager notices that defect rates spike every Monday morning. Which analytical approach best identifies the root cause?
- Pareto analysis
- Time-series disaggregation by shift and day (Correct answer)
- Scatter plot correlation
- Control chart monitoring
Correct answer: Time-series disaggregation by shift and day
Time-series disaggregation breaks data by time segments (shift, day) to isolate patterns linked to specific operational conditions like Monday startup procedures.
Question 2: When using a decision matrix to choose between capital equipment options, which scoring approach ensures objectivity?
- Score options based on cost alone
- Weight criteria by importance, then score each option against each criterion (Correct answer)
- Select the option with the most favorable reviews
- Rank options by vendor reputation
Correct answer: Weight criteria by importance, then score each option against each criterion
A weighted decision matrix assigns importance weights to criteria before scoring, preventing any single factor from dominating the decision.
Question 3: A plant manager wants to reduce inventory carrying costs. Which data metric is most directly relevant?
- Order fill rate
- Inventory turnover ratio (Correct answer)
- Supplier lead time variance
- Customer satisfaction score
Correct answer: Inventory turnover ratio
Inventory turnover ratio measures how frequently inventory is sold and replaced, directly indicating carrying cost efficiency.
Question 4: What does a p-value below 0.05 indicate in an operational hypothesis test?
- The sample size was too small
- There is a 5% chance the observed effect is real
- The result is statistically significant at the 95% confidence level (Correct answer)
- The null hypothesis is proven correct
Correct answer: The result is statistically significant at the 95% confidence level
A p-value below 0.05 means there is less than a 5% probability that the observed result occurred by chance, indicating statistical significance.
Question 5: An operations team is comparing two process improvement methods. Which statistical test is most appropriate for comparing their mean output rates?
- Chi-square test
- Two-sample t-test (Correct answer)
- ANOVA with multiple factors
- Regression analysis
Correct answer: Two-sample t-test
A two-sample t-test is designed to determine whether the means of two independent groups are statistically different from each other.
Question 6: Which type of data visualization is best suited for showing the distribution of cycle times across a production run?
- Pie chart
- Line graph
- Histogram (Correct answer)
- Gantt chart
Correct answer: Histogram
A histogram displays the frequency distribution of continuous data like cycle times, revealing shape, spread, and central tendency.
Question 7: An operations manager uses exponential smoothing for demand forecasting. What does a smoothing factor (α) close to 1.0 indicate?
- Greater weight is given to historical averages
- The forecast relies almost entirely on the most recent data point (Correct answer)
- Seasonality is being accounted for
- Long-term trends dominate the forecast
Correct answer: The forecast relies almost entirely on the most recent data point
An α close to 1.0 makes the forecast highly reactive by weighting the most recent observation almost exclusively.
COM Data Analysis & Decision Making 2
A operations manager notices that defect rates spike every Monday morning.
Which analytical approach best identifies the root cause?