CIM Lean Inventory & JIT Systems 3 — Questions and Answers
Question 1: The '5S' methodology in lean includes Sort, Set in Order, Shine, Standardize, and:
- Schedule
- Sustain (Correct answer)
- Simplify
- Synchronize
Correct answer: Sustain
Sustain (Shitsuke) ensures the 5S discipline is maintained over time through training and audits rather than reverting to old habits.
Question 2: Which waste category in the Toyota Production System refers to excess inventory beyond immediate production needs?
- Motion waste
- Overproduction waste
- Inventory waste (Correct answer)
- Waiting waste
Correct answer: Inventory waste
Inventory waste (one of the seven muda) specifically covers any stock beyond the minimum needed to keep production flowing.
Question 3: A lean team conducts a 'gemba walk.' What is the primary purpose of this activity?
- Reviewing production KPIs from management reports
- Going to the actual workplace to observe real processes and identify waste (Correct answer)
- Auditing supplier quality documentation
- Performing root cause analysis on defect data
Correct answer: Going to the actual workplace to observe real processes and identify waste
Gemba walks involve direct observation at the point of work to see waste and inefficiencies that data reports often miss.
Question 4: In lean inventory thinking, which condition justifies holding safety stock?
- Standard production runs with predictable demand
- Demand variability or supply uncertainty that cannot yet be eliminated (Correct answer)
- High product value requiring extra control
- Low inventory turnover items
Correct answer: Demand variability or supply uncertainty that cannot yet be eliminated
Safety stock is a temporary buffer for variability; lean aims to reduce variability so safety stock can eventually be minimized.
Question 5: What is the main difference between 'push' and 'pull' production systems?
- Push systems use kanban; pull systems use MRP schedules
- Push systems produce based on forecasts; pull systems produce only in response to actual demand (Correct answer)
- Push systems are manual; pull systems are automated
- Push systems suit high-volume products; pull systems suit low-volume products
Correct answer: Push systems produce based on forecasts; pull systems produce only in response to actual demand
Pull systems replenish only what has been consumed, eliminating the forecast-driven overproduction that generates excess inventory.
Question 6: Which metric best measures the effectiveness of a JIT inventory system?
- Gross margin return on inventory investment (GMROI)
- Inventory turnover ratio (Correct answer)
- Days sales of inventory (DSI)
- Fill rate percentage
Correct answer: Inventory turnover ratio
High inventory turnover indicates stock is moving quickly through the system with minimal time spent sitting idle, which is the hallmark of JIT.
Question 7: A value stream map (VSM) reveals that 90% of a product's lead time is spent waiting between process steps. What lean action is most appropriate?
- Increase batch sizes to reduce setup frequency
- Redesign the flow to enable single-piece flow and eliminate waiting (Correct answer)
- Add buffer inventory between steps to keep workers busy
- Hire additional workers at bottleneck stations
Correct answer: Redesign the flow to enable single-piece flow and eliminate waiting
VSM exposes non-value-added waiting time; the lean response is to redesign flow so parts move immediately from step to step.
CIM Lean Inventory & JIT Systems 3
The '5S' methodology in lean includes Sort, Set in Order, Shine, Standardize, and: