Question 1

Which of the following is NOT one of the 8 wastes (DOWNTIME) in Lean?

Accepted Answer

The 8 Lean wastes are captured in DOWNTIME: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion, Extra-processing. Automation is not a waste — it is often a tool to eliminate waste. The 8th waste (non-utilized talent) is sometimes omitted in the older TPS '7 wastes' model.

Question 2

A Value Stream Map (VSM) primarily helps a team:

Accepted Answer

A Value Stream Map shows the complete flow of materials and information from raw material to customer, with cycle times, inventory levels, and wait times at each step. It distinguishes value-added from non-value-added (waste) activities, enabling targeted improvement. VSM is a core Lean tool typically used in the Analyse phase.

Question 3

In the 5S methodology, what does the third 'S' (Shine / Seiso) mean?

Accepted Answer

The 5S steps are: Sort (Seiri) — remove unneeded items; Set in order (Seiton) — organize what remains; Shine (Seiso) — clean and inspect; Standardize (Seiketsu) — create standards for the first three S's; Sustain (Shitsuke) — maintain discipline. Shine also serves as an inspection — cleaning reveals abnormalities like leaks and worn parts.

Question 4

Poka-yoke refers to:

Accepted Answer

Poka-yoke (mistake-proofing or error-proofing) is a Lean technique developed by Shigeo Shingo. A poka-yoke prevents defects by making errors physically impossible (prevention type) or immediately detectable (detection type). Examples: USB connectors that only insert one way, a checklist that won't advance unless all fields are complete.

Question 5

What is kaizen?

Accepted Answer

Kaizen (Japanese: 改善, 'change for the better') is the philosophy of continuous, incremental improvement — small, frequent changes made by everyone, every day, at every level. Kaizen events (blitzes) are intensive, short-duration improvement workshops focused on a specific process area. Kaizen is a foundational element of the Toyota Production System.

Question 6

A value stream map shows a large 'push' triangle between two process steps with 3,200 units of WIP. What lean waste does this represent?

Accepted Answer

In a value stream map, a push triangle indicates inventory being pushed to the next step regardless of demand. Large WIP buffers between steps indicate overproduction — the worst of the 7 wastes — because it hides other problems and ties up capital.

Question 7

A company implements single-piece flow to replace batch processing. What is the primary benefit?

Accepted Answer

Single-piece flow (one-piece flow) moves one unit at a time through the process. When a defect occurs, it is caught immediately at the next step rather than discovered after an entire batch has been produced — dramatically reducing defect propagation and rework.

Question 8

Which lean concept refers to the practice of stopping production immediately when a defect or abnormality is detected?

Accepted Answer

Jidoka — one of the two pillars of the Toyota Production System — gives machines and workers the authority to stop production when a problem is detected. This prevents defects from moving downstream and forces immediate root cause analysis.

Question 9

Heijunka refers to which lean production concept?

Accepted Answer

Heijunka is the practice of leveling production volume and product mix over a given time period to reduce variability, stabilize the supply chain, and avoid the mura (unevenness) and muri (overburden) wastes that result from feast-famine production schedules.

Question 10

In a 5S implementation, what does the 'Sustain' step (Shitsuke) require?

Accepted Answer

Sustain (Shitsuke) is the hardest 5S step — it requires training, audits, and cultural reinforcement to ensure Sort, Set in Order, Shine, and Standardize become ongoing habits rather than one-time events. Without Sustain, workplaces revert to their original state.

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