CPT CPT Production Planning & Scheduling 4 — Questions and Answers
Question 1: A production scheduler notices that a machine has been down for 4 hours unexpectedly. Which metric is most directly impacted?
- Overall Equipment Effectiveness (OEE) (Correct answer)
- Mean Time Between Failures (MTBF)
- Takt time
- First pass yield
Correct answer: Overall Equipment Effectiveness (OEE)
OEE measures availability, performance, and quality, so unplanned downtime directly reduces the availability component of OEE.
Question 2: In a pull-based production system, work orders are released based on:
- A fixed schedule created weeks in advance
- Signals from downstream consumption or demand (Correct answer)
- The capacity of the first operation
- Forecasted demand from marketing
Correct answer: Signals from downstream consumption or demand
Pull systems release production work only when downstream processes signal a need, preventing overproduction.
Question 3: Which scheduling technique assigns jobs to machines by processing the shortest job first?
- First In First Out (FIFO)
- Shortest Processing Time (SPT) (Correct answer)
- Longest Processing Time (LPT)
- Critical Ratio (CR)
Correct answer: Shortest Processing Time (SPT)
SPT prioritizes the job with the least processing time, minimizing average flow time and work-in-process.
Question 4: A plant produces 500 units per 8-hour shift. The takt time is 1 minute per unit. If a bottleneck station can only produce 420 units per shift, what is the best immediate action?
- Increase the shift length to 10 hours
- Add overtime or a second operator at the bottleneck (Correct answer)
- Reduce the production target to 420 units
- Increase inventory buffers before the bottleneck
Correct answer: Add overtime or a second operator at the bottleneck
Adding capacity at the bottleneck directly addresses the constraint limiting throughput to below customer takt requirements.
Question 5: What does a Gantt chart primarily display in a production scheduling context?
- Inventory levels over time
- The sequence and timing of jobs across resources (Correct answer)
- Quality defect rates by shift
- Cost per unit by product line
Correct answer: The sequence and timing of jobs across resources
A Gantt chart shows tasks or jobs plotted against a time axis, illustrating when each job runs on each resource.
Question 6: When calculating net requirements in MRP, which formula is correct?
- Net Requirements = Gross Requirements + Scheduled Receipts + On-Hand Inventory
- Net Requirements = Gross Requirements − On-Hand Inventory − Scheduled Receipts (Correct answer)
- Net Requirements = Gross Requirements × Safety Stock Factor
- Net Requirements = On-Hand Inventory − Gross Requirements
Correct answer: Net Requirements = Gross Requirements − On-Hand Inventory − Scheduled Receipts
MRP subtracts available inventory (on-hand plus scheduled receipts) from gross requirements to determine what still needs to be produced or ordered.
Question 7: A company changes from monthly to weekly production planning cycles. Which benefit is most likely?
- Lower planning labor costs
- Faster response to demand changes (Correct answer)
- Reduced machine setup frequency
- Higher batch sizes per run
Correct answer: Faster response to demand changes
Shorter planning cycles allow the schedule to be updated more frequently, enabling quicker reactions to changes in customer demand or supply disruptions.
CPT CPT Production Planning & Scheduling 4
A production scheduler notices that a machine has been down for 4 hours unexpectedly.
Which metric is most directly impacted?