Lean Six Sigma Black Belt Certification Basic 2 — Questions and Answers
Question 1: Which of the following best describes the primary goal of the Control phase in DMAIC?
- Identify the root cause of defects
- Sustain improvements and prevent regression (Correct answer)
- Map the current-state process flow
- Calculate process capability
Correct answer: Sustain improvements and prevent regression
The Control phase focuses on sustaining gains by implementing monitoring systems and control plans to prevent the process from reverting to its old performance level.
Question 2: A Black Belt calculates a process sigma level of 4.5. Approximately what DPMO does this correspond to?
- 6,210
- 3,400
- 1,350 (Correct answer)
- 233
Correct answer: 1,350
A 4.5 sigma process corresponds to approximately 1,350 DPMO when using the standard 1.5-sigma shift convention.
Question 3: In a SIPOC diagram, what does the 'P' stand for?
- People
- Process (Correct answer)
- Product
- Performance
Correct answer: Process
SIPOC stands for Suppliers, Inputs, Process, Outputs, and Customers — the 'P' represents the high-level Process steps.
Question 4: Which type of data is counted in discrete units and cannot take fractional values?
- Continuous data
- Variable data
- Attribute data (Correct answer)
- Interval data
Correct answer: Attribute data
Attribute (or discrete) data consists of counts or categories, such as the number of defects or pass/fail results, and cannot be meaningfully fractional.
Question 5: The 'Voice of the Customer' (VOC) is translated into measurable product or process requirements using which tool?
- Fishbone diagram
- Quality Function Deployment (QFD) (Correct answer)
- Control chart
- Pareto chart
Correct answer: Quality Function Deployment (QFD)
Quality Function Deployment (QFD), often represented by the House of Quality matrix, systematically translates VOC needs into specific technical requirements.
Question 6: Which Lean principle focuses on producing only what is needed, when it is needed, and in the amount needed?
- Kaizen
- Poka-yoke
- Just-In-Time (JIT) (Correct answer)
- Heijunka
Correct answer: Just-In-Time (JIT)
Just-In-Time (JIT) production eliminates overproduction waste by synchronizing production output with actual demand.
Question 7: A process has a mean of 50 and a standard deviation of 2. The specification limits are 44 and 56. What is the Cp?
- 1.00 (Correct answer)
- 1.50
- 2.00
- 0.75
Correct answer: 1.00
Cp = (USL − LSL) / (6σ) = (56 − 44) / (6 × 2) = 12 / 12 = 1.00.
Lean Six Sigma Black Belt Certification Basic 2
Which of the following best describes the primary goal of the Control phase in DMAIC?