Q1. What does "Drum" represent in Drum-Buffer-Rope (DBR)?
A. Total inventory
B. The constraint setting the pace
C. The customer demand
D. The shipping buffer
✅ Answer: B. The constraint setting the pace
Q2. In DBR, what sets the rhythm for the entire production process?
A. Rope
B. Buffer
C. Constraint (Drum)
D. Inventory size
✅ Answer: C. Constraint (Drum)
Q3. What is the primary role of the "Buffer" in DBR?
A. To reduce costs
B. To store raw materials
C. To protect the constraint from fluctuations
D. To hold finished goods for shipping
✅ Answer: C. To protect the constraint from fluctuations
Q4. What does the "Rope" signal in the DBR system?
A. The availability of new orders
B. Completion of final packaging
C. Inventory consumed by the constraint
D. Number of workers needed
✅ Answer: C. Inventory consumed by the constraint
Q5. Which buffer is placed immediately before the constraint in DBR?
A. Safety Buffer
B. Shipping Buffer
C. Constraint Buffer
D. Production Buffer
✅ Answer: C. Constraint Buffer
Q6. The customer buffer is designed to:
A. Avoid raw material shortages
B. Protect the shipping schedule
C. Balance labor availability
D. Reduce overtime
✅ Answer: B. Protect the shipping schedule
Q7. Which of the following best defines a constraint in TOC?
A. An expense
B. Any resource or policy limiting system performance
C. A work schedule
D. Employee turnover
✅ Answer: B. Any resource or policy limiting system performance
Q8. What is a common form of constraint according to TOC?
A. Material defect
B. Policy constraint
C. Packaging issues
D. Supplier delays
✅ Answer: B. Policy constraint
Q9. Which of the following is not a form of constraint?
A. Physical
B. Policy
C. Paradigm
D. Location
✅ Answer: D. Location
Q10. What does a physical constraint typically refer to?
A. Beliefs and assumptions
B. Sales targets
C. Equipment, material, or space limitations
D. Market demand
✅ Answer: C. Equipment, material, or space limitations
Q11. Which of the following could be a paradigm constraint?
A. Material shortage
B. Government regulation
C. Belief in running machines constantly
D. Lack of space
✅ Answer: C. Belief in running machines constantly
Q12. What does a policy constraint usually stem from?
A. Market demand
B. Temporary delays
C. Established procedures or rules
D. Technology updates
✅ Answer: C. Established procedures or rules
Q13. Market constraints occur when:
A. Product quality is poor
B. Supply exceeds demand
C. Orders are delayed
D. Employees strike
✅ Answer: B. Supply exceeds demand
Q14. A constraint that is difficult to detect internally is often a:
A. Material issue
B. Physical constraint
C. Policy constraint
D. Customer delay
✅ Answer: C. Policy constraint
Q15. Which of the following is a typical example of a policy constraint?
A. Broken machine
B. Untrained workers
C. Union rules against cross-training
D. Product recalls
✅ Answer: C. Union rules against cross-training
Q16. Why are larger buffers sometimes required?
A. To reduce tax liability
B. To protect against variation in non-constraints
C. To increase employee performance
D. To increase throughput directly
✅ Answer: B. To protect against variation in non-constraints
Q17. What is an alternative to large buffer inventories?
A. Cycle counting
B. Safety stock
C. Sprint capacity at non-constraints
D. Kanban triggers
✅ Answer: C. Sprint capacity at non-constraints
Q18. How can a "moving constraint" be modeled in manufacturing?
A. As a breakdown
B. As multiple systems
C. As a quality check
D. As a shift schedule
✅ Answer: B. As multiple systems
Q19. Which scenario reflects a market constraint?
A. Equipment fails frequently
B. Company cannot sell what it produces
C. Union restricts overtime
D. Lack of storage space
✅ Answer: B. Company cannot sell what it produces
Q20. What usually protects the constraint from process fluctuations?
A. Safety buffer
B. Constraint buffer
C. Raw material buffer
D. Rope
✅ Answer: B. Constraint buffer
Q21. Why is the rope used in Drum-Buffer-Rope?
A. To alert the supplier about demand
B. To trigger inventory release
C. To synchronize packaging
D. To measure takt time
✅ Answer: B. To trigger inventory release
Q22. Which of the following defines a policy constraint?
A. Machinery with low speed
B. Delays due to unclear roles
C. Rule that machines must always run
D. Delivery truck breakdown
✅ Answer: C. Rule that machines must always run
Q23. A constraint buffer protects which resource?
A. Customer
B. Shipping dock
C. Bottleneck (constraint)
D. Labor availability
✅ Answer: C. Bottleneck (constraint)
Q24. Which buffer protects delivery timelines?
A. Constraint buffer
B. Safety buffer
C. Customer buffer
D. Material buffer
✅ Answer: C. Customer buffer
Q25. What causes policy constraints to persist over time?
A. Frequent training
B. High turnover
C. Deeply entrenched habits and paradigms
D. High sales pressure
✅ Answer: C. Deeply entrenched habits and paradigms
Q26. What typically makes policy constraints difficult to overcome?
A. Lack of tools
B. Management turnover
C. Resistance to change and tradition
D. Overqualified staff
✅ Answer: C. Resistance to change and tradition
Q27. Which of the following is often necessary to eliminate paradigm constraints?
A. Inventory reduction
B. Coaching and retraining
C. Automation
D. Incentives
✅ Answer: B. Coaching and retraining
Q28. What does a paradigm constraint often reflect?
A. Financial limitation
B. A long-standing belief or assumption
C. A broken conveyor system
D. Sales decline
✅ Answer: B. A long-standing belief or assumption
Q29. What is likely the result of failing to synchronize production to the constraint?
A. Increased ROI
B. Reduced WIP
C. Inventory pileups or starvation of constraint
D. More customer orders
✅ Answer: C. Inventory pileups or starvation of constraint
Q30. How does the Drum-Buffer-Rope system help improve throughput?
A. By eliminating all inventory
B. By aligning the release of materials with the constraint pace
C. By increasing fixed costs
D. By automating HR tasks
✅ Answer: B. By aligning the release of materials with the constraint pace
Q31. What does the “Drum” determine in DBR?
A. Employee productivity
B. Warehouse capacity
C. System throughput rate
D. Customer satisfaction score
✅ Answer: C. System throughput rate
Q32. Why is synchronization to the constraint important in DBR?
A. To reduce maintenance cost
B. To minimize customer contact
C. To avoid excess inventory and idle time
D. To increase tax write-offs
✅ Answer: C. To avoid excess inventory and idle time
Q33. In TOC, what typically happens to the constraint over time if improvements are made?
A. It remains fixed forever
B. It shifts to another part of the system
C. It disappears entirely
D. It creates a new policy
✅ Answer: B. It shifts to another part of the system
Q34. A policy constraint tied to bonuses for machine uptime may cause:
A. Reduced equipment wear
B. Overproduction
C. Better product quality
D. Improved customer service
✅ Answer: B. Overproduction
Q35. What’s the best way to identify hidden policy constraints?
A. Focus groups
B. Surveys
C. Bring in external consultants
D. Upgrade technology
✅ Answer: C. Bring in external consultants
Q36. Which is a non-physical type of constraint in TOC?
A. Machine breakdown
B. Lack of space
C. Union agreement
D. Shortage of raw material
✅ Answer: C. Union agreement
Q37. What happens when the Rope releases too much inventory?
A. More throughput is achieved
B. Constraint performance improves
C. Work-in-process (WIP) builds up unnecessarily
D. Delivery times improve
✅ Answer: C. Work-in-process (WIP) builds up unnecessarily
Q38. What buffer timing is typically measured in?
A. Minutes
B. Units
C. Dollars
D. Hours
✅ Answer: D. Hours
Q39. Which buffer protects from delays in upstream activities?
A. Product buffer
B. Constraint buffer
C. Productivity buffer
D. Marketing buffer
✅ Answer: B. Constraint buffer
Q40. What is one outcome of failing to maintain a sufficient constraint buffer?
A. More inventory
B. Lower demand
C. Constraint starvation
D. Higher customer satisfaction
✅ Answer: C. Constraint starvation
Q41. Why do TOC experts often recommend sprint capacity at non-constraints?
A. To maintain flexibility
B. To replace expensive buffers
C. To handle unexpected variability without large inventories
D. To monitor worker effort
✅ Answer: C. To handle unexpected variability without large inventories
Q42. Which type of constraint is rooted in outdated procedures?
A. Physical constraint
B. Market constraint
C. Policy constraint
D. Capacity constraint
✅ Answer: C. Policy constraint
Q43. A company insists on producing full batch sizes despite low demand. This reflects a:
A. Market constraint
B. Physical constraint
C. Policy or paradigm constraint
D. Investment constraint
✅ Answer: C. Policy or paradigm constraint
Q44. A system with multiple product flows may have:
A. Only one bottleneck
B. No constraints at all
C. Multiple constraints that vary per product path
D. One fixed equipment constraint
✅ Answer: C. Multiple constraints that vary per product path
Q45. Which constraint is external to the manufacturing process?
A. Raw material shortage
B. Sales below capacity
C. Operator unavailability
D. Inventory mismanagement
✅ Answer: B. Sales below capacity
Q46. According to DBR, how should materials be released into production?
A. Based on historical production data
B. Randomly across departments
C. Only when the Rope signals demand from the constraint
D. As soon as they arrive from suppliers
✅ Answer: C. Only when the Rope signals demand from the constraint
Q47. Which of these is least likely to be a constraint in a high-capacity factory?
A. Equipment breakdown
B. Outdated belief systems
C. Slow-moving inventory
D. Global demand
✅ Answer: D. Global demand
Q48. TOC recommends focusing improvement efforts:
A. Equally across all departments
B. On HR policies
C. On the current constraint
D. On automation systems
✅ Answer: C. On the current constraint
Q49. Paradigm constraints can usually be overcome with:
A. Software upgrades
B. Bonus programs
C. Training and mindset change
D. Machine replacements
✅ Answer: C. Training and mindset change
Q50. DBR helps companies achieve:
A. Just-in-time inventory
B. Maximum inventory turns
C. Synchronized flow and stable throughput
D. Minimum wage compliance
✅ Answer: C. Synchronized flow and stable throughput
Q51. The most commonly overlooked type of constraint is:
A. Physical
B. Market
C. Policy
D. Equipment
✅ Answer: C. Policy
Q52. TOC promotes identifying constraints because:
A. It reduces payroll
B. It enhances marketing ROI
C. It focuses energy where it matters most
D. It improves CRM systems
✅ Answer: C. It focuses energy where it matters most
Q53. The Drum sets the pace in a system just like:
A. Inventory size sets reorder point
B. A metronome in a band
C. Market demand sets bonus structure
D. Capacity utilization measures cost
✅ Answer: B. A metronome in a band
Q54. Which term best represents a system’s production pacemaker in TOC?
A. Rope
B. Buffer
C. Drum
D. Schedule
✅ Answer: C. Drum
Q55. What is a key outcome of implementing DBR correctly?
A. Higher taxes
B. Increased stockouts
C. Improved flow and reduced WIP
D. Lower equipment efficiency
✅ Answer: C. Improved flow and reduced WIP
Master the Theory of Constraints with 50+ MCQs on Drum-Buffer-Rope (DBR), constraint types, policy limitations, buffers, and synchronizing throughput. Great for MBA, operations, and lean management learners.
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