MRP Production Scheduling & Capacity Planning 4 — Questions and Answers
Question 1: Input/output control in production scheduling is used primarily to:
- Monitor and regulate the flow of work into and out of work centers to control queue levels (Correct answer)
- Track inventory receipts and issues from the stockroom
- Control the number of purchase orders released per week
- Measure customer order fulfillment rates
Correct answer: Monitor and regulate the flow of work into and out of work centers to control queue levels
I/O control compares planned vs. actual input and output at work centers to manage WIP queues and lead times.
Question 2: Which scheduling rule typically achieves the lowest average flow time for a set of jobs?
- Earliest Due Date (EDD)
- Longest Processing Time (LPT)
- Shortest Processing Time (SPT) (Correct answer)
- Critical Ratio (CR)
Correct answer: Shortest Processing Time (SPT)
SPT minimizes average flow time and average WIP by processing the quickest jobs first.
Question 3: A 'load profile' in capacity planning shows:
- The number of employees available by shift
- The planned workload on a resource across future time periods (Correct answer)
- The sequence of operations in a routing
- The cumulative shipment history for a customer
Correct answer: The planned workload on a resource across future time periods
A load profile charts projected work center demand over time, highlighting overloads and underloads.
Question 4: What is the effect of increasing the planning time fence in an MPS?
- It reduces the number of items in the master schedule
- It increases schedule stability by protecting more periods from automatic changes (Correct answer)
- It decreases the safety stock required
- It shortens the cumulative lead time for purchased parts
Correct answer: It increases schedule stability by protecting more periods from automatic changes
A longer planning time fence freezes more of the schedule, reducing nervousness but decreasing flexibility.
Question 5: In job shop scheduling, 'makespan' refers to:
- The total time from first job start to last job completion (Correct answer)
- The average queue time across all work centers
- The overtime hours required to complete all orders
- The difference between planned and actual completion dates
Correct answer: The total time from first job start to last job completion
Makespan is the total elapsed time to complete an entire set of jobs, from the start of the first to the finish of the last.
Question 6: Which of the following best describes 'capacity cushion'?
- Extra raw material held to buffer against supply disruptions
- The amount of capacity kept in reserve above expected demand (Correct answer)
- The difference between rated and demonstrated capacity
- Safety stock expressed as a percentage of lead time demand
Correct answer: The amount of capacity kept in reserve above expected demand
Capacity cushion is intentional excess capacity maintained to handle demand variability and unexpected surges.
Question 7: When a production planner uses 'lot splitting' to address a bottleneck, the result is:
- Combining multiple orders into one large batch
- Dividing one order into smaller batches that can be processed in parallel or overlap operations (Correct answer)
- Increasing the order quantity to improve economies of scale
- Reducing the number of operations in the routing
Correct answer: Dividing one order into smaller batches that can be processed in parallel or overlap operations
Lot splitting breaks a large order into smaller sub-lots that can start downstream operations before the entire lot is complete.
MRP Production Scheduling & Capacity Planning 4
Input/output control in production scheduling is used primarily to: