CPT Lean Manufacturing Principles 3 — Questions and Answers
Question 1: A manufacturer groups similar machines together in one area of the plant. From a lean perspective, this layout is most likely to cause which type of waste?
- Overproduction and excess inventory (Correct answer)
- Defects and rework
- Skills underutilization
- Overprocessing
Correct answer: Overproduction and excess inventory
Functional (departmental) layouts often lead to large batch production and work-in-progress inventory building up between departments.
Question 2: What is the primary goal of implementing cellular manufacturing in a lean environment?
- Increasing batch sizes for efficiency
- Reducing lead time by co-locating equipment for product families (Correct answer)
- Separating inspection from production
- Maximizing machine utilization rates
Correct answer: Reducing lead time by co-locating equipment for product families
Cellular manufacturing arranges equipment and workstations into a U-shaped or linear cell dedicated to a product family, minimizing transport and wait time.
Question 3: During a kaizen event, a team discovers that operators walk 300 feet to retrieve components. Which waste category does this fall under?
- Waiting
- Transportation
- Motion (Correct answer)
- Inventory
Correct answer: Motion
Motion waste refers to unnecessary movement of people, such as walking long distances to retrieve parts, tools, or materials.
Question 4: What does 'heijunka' mean in lean production?
- Continuous improvement through small changes
- Production leveling to smooth out volume and mix over time (Correct answer)
- Error-proofing a process to prevent mistakes
- Standardizing work procedures across shifts
Correct answer: Production leveling to smooth out volume and mix over time
Heijunka is the practice of leveling the production schedule by quantity and variety to reduce unevenness (mura) and overburden (muri).
Question 5: Which metric measures the percentage of time a process is available, performing, and producing quality output?
- Cycle time
- Overall Equipment Effectiveness (OEE) (Correct answer)
- Throughput rate
- First pass yield
Correct answer: Overall Equipment Effectiveness (OEE)
OEE combines Availability, Performance, and Quality rates into one metric to identify how effectively manufacturing equipment is being used.
Question 6: In a lean pull system, production is triggered by:
- A master production schedule pushed from planning software
- Actual downstream customer or process demand (Correct answer)
- Supervisory directives at the start of each shift
- Forecasted demand from sales projections
Correct answer: Actual downstream customer or process demand
A pull system produces only in response to actual demand signals from downstream processes or customers, reducing overproduction and excess inventory.
Question 7: What is the purpose of a 'red tag' in a 5S implementation?
- To indicate items that are urgently needed at the workstation
- To identify items that are questionable and may not belong in the work area (Correct answer)
- To mark hazardous materials for safety warnings
- To signal that a machine requires immediate repair
Correct answer: To identify items that are questionable and may not belong in the work area
Red tags are applied during the Sort step of 5S to items whose necessity is uncertain, placing them in a red-tag holding area for evaluation.
CPT Lean Manufacturing Principles 3
A manufacturer groups similar machines together in one area of the plant.
From a lean perspective, this layout is most likely to cause which type of waste?