Define Phase

The correct answer states that cleaning should be thorough and systematic, including all areas regardless of visibility. This best reinforces proper Seiso (Shine) implementation because:

Seiso is the third pillar of 5S methodology and emphasizes thorough cleaning of the entire workplace, not just visible or convenient areas. The purpose of Shine goes beyond aesthetics - it serves to:
1. Identify abnormalities and potential equipment problems early
2. Maintain equipment in optimal condition
3. Create a safe working environment
4. Establish cleaning as inspection

Hidden areas behind equipment often harbor dust, debris, and contamination that can lead to equipment failures, safety hazards, or quality issues. A systematic approach ensures no area is overlooked.

The second option is incorrect because focusing only on customer-facing and high-traffic areas defeats the purpose of Seiso. Hidden contamination behind equipment can still cause problems regardless of whether customers see it.

The third option is incorrect because extending time for accessible surfaces doesn't address the core issue - employees are skipping hard-to-reach areas entirely. More time for easy areas won't improve coverage of difficult areas.

The fourth option is incorrect because it still focuses on frequently touched surfaces and equipment exteriors, which perpetuates the problem of neglecting hidden areas. Proper Seiso requires attention to ALL areas, including those behind and underneath equipment.

The correct answer is Correction/Defects waste resulting from errors requiring rework.

In Lean Six Sigma, there are eight types of waste (often remembered by the acronym DOWNTIME or TIMWOODS). The scenario describes a situation where price tags are printed with errors (12% defect rate), and employees must:
- Identify the mistakes
- Dispose of incorrect tags
- Create new replacement tags

This is a classic example of Defects/Correction waste. Defects waste occurs when products or outputs do not meet specifications and require additional effort to fix, rework, or redo. The time, materials, and labor spent on reprinting price tags represents non-value-added activity caused by quality failures in the initial process.

The other options are incorrect because:

Overproduction waste refers to making more of something than is needed or making it sooner than required. The scenario describes correcting errors, not producing excess quantities of tags.

Motion waste involves unnecessary physical movements by workers, such as reaching, walking, or bending. While employees do move to handle the reprinting process, the root cause of the inefficiency is the defects themselves, not the movements.

Transportation waste deals with unnecessary movement of materials, products, or information between processes or locations. The scenario focuses on errors in printing and the subsequent rework, not on moving tags between different locations.

Rolled Throughput Yield (RTY) is calculated by multiplying the individual yields of each process step together.

For this three-step process:
RTY = 0.90 × 0.85 × 0.95
RTY = 0.765 × 0.95
RTY = 0.72675

This rounds to approximately 0.727 or 72.7%.

The other answers are incorrect because:

• Taking the average of the yields (0.90 + 0.85 + 0.95) ÷ 3 = 0.90 or 90% is not how RTY is calculated. Averaging would overstate the actual throughput capability of the process.

• Using the lowest individual step yield as a bottleneck (0.85 or 85%) does not account for the cumulative effect of defects at each step. Each step contributes to overall yield loss.

• Adding defect rates and subtracting from 100% would give: 1 - (0.10 + 0.15 + 0.05) = 1 - 0.30 = 0.70 or 70%. This method incorrectly assumes defect rates are additive, which overstates the total defect rate and understates the true RTY.

The multiplication method correctly reflects that a unit must pass through ALL steps successfully to be considered good output.