Week 5 Flashcards
What is the difference between planning and control?
Planning is a formalization of what is intended to happen in the future.
✅ Control is the process of coping with changes and making interventions to keep operations on track.
Why is planning important in operations management?
It ensures that resources are allocated efficiently and operations run smoothly to meet demand.
Why is control necessary in operations?
Because real-world conditions do not always match the plan, and adjustments are needed to stay on track.
What are the three levels of planning and control?
Long-term – Determines overall resource levels using aggregated forecasts.
✅ Medium-term – Balances resources with expected demand fluctuations.
✅ Short-term – Responds to actual demand and makes real-time adjustments.
What are the objectives of long-term planning?
Resource planning in financial terms, ensuring future capacity is sufficient.
What are the objectives of medium-term planning?
Balancing financial and operational goals by adjusting resources as needed
What are the objectives of short-term planning?
Making quick operational interventions to correct deviations from the plan.
What are the key types of uncertainty in operations management?
Demand uncertainty – When, what, and how much customers will buy.
✅ Supply uncertainty – When deliveries will arrive, how much can be ordered, and product quality issues.
What causes time-related supply uncertainty?
Unexpected delays in transport, supplier deliveries, or process durations.
What causes quantity-related supply uncertainty?
Errors in shipping, storage documentation, or spoilage of perishable goods
What causes quality-related supply uncertainty?
Damage during transport, incorrect handling, or storage issues.
What makes demand difficult to predict?
It is highly variable, influenced by seasonality, time of day, and unexpected changes.
What is seasonality in demand?
A variation that repeats itself at fixed intervals over a year (e.g., ice cream sales in summer).
What factors cause seasonal demand patterns?
Weather, holidays, work schedules, and recurring events (e.g., tax processing peaks).
hat are peak demand periods?
High demand fluctuations in short time intervals (e.g., traffic rush hours, hospital emergencies on weekends).
What is a one-off peak demand?
A large temporary increase in demand that happens only once (e.g., film premieres, product launches).
How do businesses manage unpredictable demand variations?
Through strategies like overbooking (airlines, hotels) and demand forecasting models.
What is independent demand?
Demand for a finished product (e.g., a bicycle, a pizza, or a laptop).
What is dependent demand?
Demand for components used to make a finished product (e.g., wheels for a bicycle, cheese for pizza).
Why is independent demand harder to predict?
Because it depends on external customer preferences and market trends.
Why is dependent demand easier to predict?
Because it is calculated based on the required amount of finished products.
What is loading in operations?
It is the amount of work allocated to a work center or resource.
What reduces available time for valuable operating activities?
Quality losses, machine breakdowns, setup time, and idling equipment.
What is finite loading?
Allocates work within available capacity, even if jobs are delayed.
What is infinite loading?
Allocates work without capacity restrictions, assuming jobs must be completed on time.
What type of loading does an Accident & Emergency (A&E) hospital department use?
Infinite loading – because it must handle all patients, regardless of capacity limits.
What is sequencing in planning and control?
It is the process of determining the order in which tasks/jobs are completed.
What factors influence sequencing decisions?
Physical constraints, customer priorities, and operational efficiency.
What is Due Date (DD) sequencing?
Jobs are completed based on when they are due for delivery.
What are the advantages of Due Date sequencing?
Improves delivery dependability and customer satisfaction.
What is Last In, First Out (LIFO) sequencing?
The most recent jobs are processed first (e.g., materials packed in a box).
What is First In, First Out (FIFO) sequencing?
Jobs are processed in the order they arrive (e.g., mail or document processing).
What is Longest Operation Time (LOT) sequencing?
The longest jobs are completed first, maximizing resource utilization.
What is Shortest Operation Time (SOT) sequencing?
The quickest jobs are completed first, which is useful for fast cash-flow businesses.
Can airline passengers be sequenced?
Yes, different boarding methods impact efficiency.
What was the fastest airline boarding method in Boeing 757 experiments?
Randomized boarding (passengers enter in small groups rather than row-by-row).
What is sequencing in operations?
It determines the order in which tasks/jobs are completed
What factors influence sequencing decisions?
Physical constraints, customer priorities, and efficiency considerations.
What is First In, First Out (FIFO) sequencing?
Jobs are completed in the order they arrive (e.g., processing documents).
What is Last In, First Out (LIFO) sequencing?
The most recent jobs are completed first (e.g., unloading stacked containers).
What is Due Date (DD) sequencing?
Jobs are completed in order of earliest due date to improve delivery dependability.
What is Shortest Operation Time (SOT) sequencing?
Jobs with the shortest processing time are completed first, reducing waiting time.
What is Longest Operation Time (LOT) sequencing?
Jobs with the longest processing time are completed first, maximizing machine utilization.
Which sequencing method minimizes total time in process?
SOT (Shortest Operation Time).
Which sequencing method minimizes total lateness?
Due Date (DD) rule.
Which sequencing method ensures fairness in job order?
FIFO (First In, First Out).
Which sequencing method maximizes resource utilization?
LOT (Longest Operation Time).
Which sequencing method is commonly used for materials packed in stacks or containers?
LIFO (Last In, First Out).
What is scheduling in operations?
Scheduling determines when jobs should start and finish to meet deadlines.
What are the two main types of scheduling?
Forward Scheduling – Jobs start as soon as they arrive.
✅ Backward Scheduling – Jobs start at the latest possible time to meet deadlines.
What is a Gantt chart used for in scheduling?
A visual tool that shows the timeline of tasks, their start/end times, and dependencies.
How is scheduling used in daily life?
Examples include class schedules, train timetables, hospital appointments, and production plans.
What is Material Requirements Planning (MRP)?
A scheduling system used to determine when and how much raw
materials/components are needed for production.
What are the main steps in MRP?
Determine future demand using forecasts and customer orders.
Create a master schedule to outline production needs.
Calculate dependent demand for components.
Use Bill of Materials (BOM) to list required parts.
Offset demand by lead time to determine order release dates.
What is a Bill of Materials (BOM)?
A list of materials, components, and subassemblies required to manufacture a product
How does MRP calculate net requirements?
Net Requirements =
Gross Requirements – (Inventory + Scheduled Receipts).
What is “exploding the BOM” in MRP?
It calculates the total quantity of materials needed at all production levels.
How does lead time affect MRP?
Lead time offset ensures that materials are ordered in advance to match production schedules.
If 10 finished items are needed in April, how does MRP determine component demand?
MRP traces demand backward through the BOM, considering lead times to calculate how many subcomponents must be ordered.
What is the purpose of MRP?
MRP helps determine when and how much raw materials and components are needed for production
What are the key steps in MRP?
Identify demand – Determine how many finished products are needed.
Create a Master Schedule – Plan production based on demand.
Calculate component requirements – Use the Bill of Materials (BOM) to break down materials needed.
Offset by lead time – Schedule orders so materials arrive on time.
What is a Bill of Materials (BOM)?
A detailed list of parts, components, and raw materials needed to manufacture a product.
How does MRP calculate net requirements?
Net Requirements =
Gross Requirements – (Inventory + Scheduled Receipts)
What is the importance of lead time in MRP?
Orders must be placed in advance to ensure materials arrive before production starts.
What happens if demand increases suddenly in MRP?
The system must adjust orders and re-plan production to meet new demand
If 10 units of a product are needed in April, when should components be ordered?
Since lead time is 1 month, components should be ordered in March.
How does MRP “explode the BOM”?
It calculates how many subcomponents are needed for each finished product.
Example: If 1 unit of Component A is needed for each finished product, then 10 units of Component A are required for 10 products.
What happens if a component is used in multiple products?
MRP aggregates total demand across all products using that component.
Why is monitoring and control important in operations management?
It ensures that plans match reality and adjustments can be made if needed
What causes deviations from an operations plan?
Supply chain disruptions, unexpected demand changes, equipment failures, and staff shortages.
at are the two main intervention methods in operations control?
Push System and Pull System
What is a Push System in planning and control?
Production is scheduled in advance based on forecasted demand and moves forward as planned.
What are the problems with Push Systems?
Overproduction leading to high inventory costs.
Idle time due to mismatched production rates.
Queues and delays when one stage slows down.
What is an example of a Push System?
Mass production, military operations, large-scale food production.
What is a Pull System in planning and control?
Work is triggered only when there is actual demand (materials move when needed).
Why are Pull Systems used in Lean Operations?
They reduce waste and inventory by only producing what is needed.
What are the risks of a Pull System?
Highly sensitive to delays – if one stage stops, the whole process is affected.
What are examples of a Pull System?
Just-In-Time (JIT) car production, hospital triage systems, computer repair services.
Which system is better for stable demand?
Pull System – Works well when demand is predictable.
Which system is better for large-scale production?
Push System – Helps in mass production where demand forecasting is essential.
Which system minimizes inventory storage costs?
Pull System – Reduces excess stock and avoids overproduction.
Which system is more flexible to demand changes?
Pull System – Can adapt quickly if customer needs change.
What is an example of a Push System in the food industry?
Pre-made sandwiches at a supermarket – produced based on forecasted demand.
What is an example of a Pull System in the food industry?
Made-to-order sandwiches at a restaurant – prepared only when ordered.
Which system is used in car manufacturing?
Pull System (Just-In-Time production) – Materials arrive only when needed for assembly.
How can businesses track if operations are on schedule?
By using performance indicators like on-time delivery rates, production output, and inventory levels.
What happens when production deviates from the plan?
Managers must re-plan or adjust resources to bring operations back on track.
What role does technology play in monitoring operations?
Systems like ERP (Enterprise Resource Planning) and real-time tracking help monitor and adjust plans quickly.
