BSIE Production Management 5 โ Questions and Answers
Question 1: A facility produces three products with contribution margins of $30, $50, and $45 per unit and machine-hour requirements of 3, 5, and 3 hours respectively. If machine hours are the binding constraint, which product should be prioritized?
- Product 1 ($30/unit)
- Product 2 ($50/unit)
- Product 3 ($45/unit) (Correct answer)
- All products equally, based on demand
Correct answer: Product 3 ($45/unit)
Product 3 yields $45 รท 3 = $15/machine-hour, higher than Product 1 ($10/hr) and Product 2 ($10/hr), so it should be prioritized.
Question 2: The average waiting time in an M/M/1 queue increases dramatically as server utilization (ฯ) approaches:
- 0.5 (50%)
- 0.75 (75%)
- 1.0 (100%) (Correct answer)
- 1.25 (125%)
Correct answer: 1.0 (100%)
As ฯ โ 1, the queue length and waiting time grow toward infinity; the system becomes unstable at full utilization.
Question 3: In lean manufacturing, 'Jidoka' (autonomation) refers to:
- Balancing production flow to match takt time
- The authority and mechanism to stop production when a defect is detected (Correct answer)
- Continuous improvement through small incremental changes
- Standardizing work sequences to reduce variability
Correct answer: The authority and mechanism to stop production when a defect is detected
Jidoka gives machines and workers the ability to detect abnormalities and stop the line, preventing defects from passing downstream.
Question 4: Which forecasting method uses a weighted average of past observations where more recent data receives exponentially greater weight?
- Simple moving average
- Exponential smoothing (Correct answer)
- Linear regression
- Box-Jenkins ARIMA
Correct answer: Exponential smoothing
Exponential smoothing assigns geometrically declining weights to older observations, with ฮฑ controlling the decay rate.
Question 5: Total Productive Maintenance (TPM) aims to maximize equipment effectiveness by involving:
- Only certified maintenance technicians
- Equipment operators in routine maintenance tasks (Correct answer)
- External contractors for all preventive maintenance
- Quality engineers in failure mode analysis exclusively
Correct answer: Equipment operators in routine maintenance tasks
TPM empowers production operators to perform basic maintenance, cleaning, and inspections to prevent equipment deterioration.
Question 6: In aggregate production planning, which cost is incurred when production output is less than demand and orders cannot be fulfilled on time?
- Holding cost
- Backorder or shortage cost (Correct answer)
- Hiring cost
- Overtime cost
Correct answer: Backorder or shortage cost
Backorder (shortage) costs represent lost sales, expediting expenses, and customer dissatisfaction from unmet demand.
Question 7: A p-chart in statistical process control is used to monitor:
- The mean and range of a continuous measurement
- The number of defects per unit in a sample
- The proportion of defective items in a sample (Correct answer)
- The time between successive defective events
Correct answer: The proportion of defective items in a sample
The p-chart tracks the fraction (proportion) of nonconforming items in subgroups of varying or fixed size.
BSIE Production Management 5
A facility produces three products with contribution margins of $30, $50, and $45 per unit and machine-hour requirements of 3, 5, and 3 hours respectively.
If machine hours are the binding constraint, which product should be prioritized?