CPM Plant Layout & Material Flow 3 — Questions and Answers
Question 1: What does the term 'spaghetti diagram' refer to in plant layout analysis?
- A chart showing machine downtime patterns
- A diagram tracing the actual travel path of a product or worker through the facility (Correct answer)
- A schematic of piping and instrumentation
- A network diagram of supplier relationships
Correct answer: A diagram tracing the actual travel path of a product or worker through the facility
A spaghetti diagram maps all the actual movement paths in a facility, revealing excessive travel distances and inefficient layouts.
Question 2: Which type of storage system uses horizontal carousels or vertical lift modules to bring parts to the picker?
- Conventional pallet rack
- Automated Storage and Retrieval System (AS/RS)
- Goods-to-person system (Correct answer)
- Drive-in rack
Correct answer: Goods-to-person system
Goods-to-person systems (carousels, VLMs, mini-loads) bring items to a stationary picker, reducing travel time and improving ergonomics.
Question 3: A plant uses 'zone picking' in its warehouse. This strategy primarily improves:
- Receiving dock throughput
- Order picking productivity by assigning pickers to fixed areas (Correct answer)
- Cycle counting accuracy
- Supplier lead time
Correct answer: Order picking productivity by assigning pickers to fixed areas
Zone picking assigns each picker to a specific storage zone, reducing travel distance and allowing specialization for faster order fulfillment.
Question 4: Which layout analysis tool assigns a numerical score to alternative plant layouts based on weighted criteria?
- Block diagram
- Space relationship diagram
- Muther's Systematic Layout Planning (SLP) scoring matrix (Correct answer)
- Value stream map
Correct answer: Muther's Systematic Layout Planning (SLP) scoring matrix
SLP's rating/scoring approach evaluates each layout alternative against weighted factors (flow, safety, flexibility) to select the best option.
Question 5: In material flow analysis, 'backtracking' refers to:
- Returning defective products to suppliers
- Material moving backward against the primary flow direction (Correct answer)
- Auditing inventory records against physical counts
- Reprocessing scrap within the same machine
Correct answer: Material moving backward against the primary flow direction
Backtracking occurs when material moves in the reverse direction of the main production flow, adding travel distance and disrupting throughput.
Question 6: A cross-docking operation eliminates which warehouse activity?
- Receiving
- Sorting and consolidation
- Long-term storage (Correct answer)
- Outbound shipping
Correct answer: Long-term storage
Cross-docking transfers inbound goods directly to outbound transport with minimal or no storage, eliminating the need for long-term warehousing.
Question 7: Which of the following BEST describes the 'unit load' principle in material handling?
- Each part is moved individually to minimize damage
- Moving the largest practical quantity in a single handling event to reduce trips (Correct answer)
- Using the lightest possible container to reduce ergonomic risk
- Assigning one worker per load at all times
Correct answer: Moving the largest practical quantity in a single handling event to reduce trips
The unit load principle maximizes the size of each move (pallet, tote, container) to minimize the number of handling events and total cost.
CPM Plant Layout & Material Flow 3
What does the term 'spaghetti diagram' refer to in plant layout analysis?