Lean Manufacturing & Waste Reduction Flashcards

Which lean concept describes the ideal state where every process step adds value with zero waste?

Answer: Perfection (the fifth lean principle)

Perfection is the fifth lean principle, representing the ideal end-state where all waste is eliminated and every step adds customer value.

A factory produces 500 units/day with a net available time of 27,000 seconds/day. What is the takt time?

Answer: 54 seconds

Takt time = available time ÷ customer demand = 27,000 ÷ 500 = 54 seconds per unit.

What is the primary purpose of a Heijunka box in lean production?

Answer: Level production volume and mix over time

A Heijunka box is a visual scheduling tool that levels production by distributing orders evenly across a time period to smooth demand fluctuations.

In the context of the 7 wastes (Muda), which category does a worker walking across the plant floor to retrieve a tool represent?

Answer: Motion

Unnecessary movement of people is classified as Motion waste, whereas Transportation refers to unnecessary movement of materials or products.

What does OEE measure in a lean manufacturing environment?

Answer: Overall Equipment Effectiveness combining availability, performance, and quality

OEE (Overall Equipment Effectiveness) is the product of Availability × Performance × Quality and benchmarks how effectively equipment is utilized.

Which waste reduction technique uses red tags to identify and remove unnecessary items from the workplace?

Answer: Red-tag campaign (5S Sort phase)

Red-tagging is the core activity of the Sort (Seiri) step in 5S, where unneeded items are tagged and removed from the work area.

A value stream map shows a process with a Process Cycle Efficiency (PCE) of 8%. What does this indicate?

Answer: Only 8% of total lead time is value-added time

PCE = value-added time ÷ total lead time; a PCE of 8% means 92% of lead time is consumed by non-value-added activities (waste).