10 free, exam-style ASQ Certified Six Sigma Black Belt (CSSBB) practice questions with answers and
explanations. No signup required. Work through them below, then take the
full free CSSBB practice test to study every exam domain.
These 10 free CSSBB questions are organized by exam domain, so you can see how each part of the ASQ Certified Six Sigma Black Belt blueprint is tested. Reveal the answer and explanation under each question.
Domain 4: Define 13% of exam
Question 1
Early in the Define phase, a team needs a high-level view of a process that identifies who supplies inputs, what the process does, and who receives the outputs. Which tool is MOST appropriate?
- A detailed value stream map
- A SIPOC diagram
- A cause-and-effect (fishbone) diagram
- A control plan
Show answer & explanation
Correct answer: B - A SIPOC diagram
Domain 5: Measure 17% of exam
Question 2
A process has a Cp of 1.67 but a Cpk of 1.00. Both specification limits are fixed. What is the MOST likely conclusion?
- The measurement system is unreliable and must be re-evaluated
- The process spread is too wide for the specification
- The process is not centered between the specification limits
- The process is incapable and cannot meet specification
Show answer & explanation
Correct answer: C - The process is not centered between the specification limits
Question 3
A product passes through four sequential process steps with first pass yields of 98%, 95%, 99%, and 97%. What is the rolled throughput yield (RTY)?
- About 97.3%
- About 89.4%
- Exactly 95.0%
- About 99.0%
Show answer & explanation
Correct answer: B - About 89.4%
Question 4
During a Gauge R&R study, the SAME operator measures the same part with the same instrument several times and gets noticeably different readings. This variation is BEST described as:
- Reproducibility (variation between appraisers)
- Bias (offset from the true reference value)
- Repeatability (variation within one appraiser)
- Linearity (bias changing across the range)
Show answer & explanation
Correct answer: C - Repeatability (variation within one appraiser)
Domain 6: Analyze 15% of exam
Question 5
A Black Belt wants to determine whether the mean cycle time differs among five machines using a single analysis. Which statistical test is MOST appropriate?
- Two-sample t-test
- Paired t-test
- Chi-square goodness-of-fit test
- One-way ANOVA
Show answer & explanation
Correct answer: D - One-way ANOVA
Question 6
A team concludes that a process change improved performance when, in reality, it had no effect. In hypothesis testing terms, this error is:
- A Type I error, occurring with probability alpha
- A Type II error, occurring with probability beta
- An increase in the test's statistical power
- An error caused by too small a sample size
Show answer & explanation
Correct answer: A - A Type I error, occurring with probability alpha
Question 7
In an FMEA, a failure mode is rated Severity = 7, Occurrence = 4, and Detection = 6. What is its Risk Priority Number (RPN)?
- 17
- 28
- 168
- 42
Show answer & explanation
Correct answer: C - 168
Domain 7: Improve 14% of exam
Question 8
A team plans a full factorial experiment with three factors, each set at two levels, with no replication. How many experimental runs are required?
- 6 runs
- 8 runs
- 9 runs
- 16 runs
Show answer & explanation
Correct answer: B - 8 runs
Question 9
Equipment changeover on a line takes 50 minutes, forcing large batch sizes and excess inventory. Which Lean method DIRECTLY targets this problem?
- 5S workplace organization and standardization
- Single-Minute Exchange of Dies (SMED)
- Poka-yoke error-proofing of the operation
- Total Productive Maintenance (TPM) program
Show answer & explanation
Correct answer: B - Single-Minute Exchange of Dies (SMED)
Domain 8: Control 11% of exam
Question 10
A new analyst sets the upper and lower control limits on an X-bar chart equal to the customer's specification limits. Why is this incorrect?
- Control limits should be plus or minus two sigma, not three sigma
- Specification limits are required to be wider than the control limits
- Control limits come from the process; specifications come from the customer
- Control limits apply only to attribute charts, never to variable charts
Show answer & explanation
Correct answer: C - Control limits come from the process; specifications come from the customer
The rest of the CSSBB blueprint
The CSSBB exam also covers these domains. Drill them in the full free practice test:
- Domain 1: Organization-Wide Planning and Deployment 8% of exam
- Domain 2: Organizational Process Management and Measures 8% of exam
- Domain 3: Team Management 10% of exam
- Domain 9: Design for Six Sigma (DFSS) Framework and Methodologies 4% of exam