10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The LSSBB exam has 80 questions and runs 2 hours 30 minutes.
These 10 free LSSBB questions are organized by exam domain, so you can see how each part of the Lean Six Sigma Black Belt blueprint is tested. Reveal the answer and explanation under each question.
Video of a press changeover shows the operator stopping the press, then locating and presetting the next die before removing the installed die. Engineering confirms that locating and presetting can be completed at a separate station while the current batch runs; die removal still requires the approved shutdown procedure. A SMED improvement should change the sequence by:
Correct answer: A - Locating and presetting the next die before stopping the press.
Customer demand for a machining line exceeds its output. The confirmed constraint is the middle operation; the three sequential operations can sustain 120, 80, and 110 conforming parts per shift, respectively. The constraint regularly waits for material while the first operation builds large batches of less urgent work. Which proposal should the Black Belt champion first?
Correct answer: B - Keep the constraint supplied and coordinate upstream releases with its production schedule.
During Hoshin Kanri deployment, executives propose a 30% reduction in order lead time. Sales agrees to the goal, but operations demonstrates that the proposed milestones exceed available capacity unless order-release rules change. The strategic direction remains sound. Which response represents catchball rather than simple target assignment?
Correct answer: B - Exchange evidence across levels and agree on aligned objectives, methods, and resources.
A service center audits a varying number of invoices each week. Every invoice is checked for the same defined error types and may contain several errors. The team wants to monitor errors per invoice audited. The assumptions for a Poisson model are satisfied. Which control chart matches this metric and sampling plan?
Correct answer: D - A u chart tracking errors per invoice, with limits reflecting each week's audit volume.
Two inspectors report different rejection rates for the same component. In a blinded study, each measures the same unchanged reference parts three times in random order, using the same gauge under the same conditions. Repeated readings of each part are tightly clustered for each inspector, but one inspector consistently reads higher than the other. Where should the investigation focus?
Correct answer: D - Reproducibility: disagreement between inspectors measuring the same parts.
In a replicated, randomized experiment, raising curing temperature increases bond strength at low pressure but decreases it at high pressure. The temperature-by-pressure interaction is statistically significant, although the average temperature main effect is close to zero. How should the temperature factor be handled?
Correct answer: A - Retain temperature and evaluate its effect separately at each pressure level; averaging masks the interaction.
Before a redesigned assembly cell restarts, an FMEA identifies a fixture-clamping failure that could eject a part toward the operator. Its estimated frequency is low and its risk priority number is lower than that of a frequent cosmetic defect. A required protective enclosure has not yet been installed. The cell is stopped for commissioning; other cells have independent safeguards and no identified related hazard. What should the Black Belt recommend?
Correct answer: C - Keep this cell out of service until the required protection is installed and validated.
During a 480-minute shift, a packaging machine has 30 minutes of breaks when no production is scheduled and 50 minutes of changeovers and breakdowns during scheduled production. It makes 720 units at an ideal cycle time of 0.5 minute per unit. Of these, 684 pass on the first attempt; the rest require rework. The plant requires an improvement review when overall equipment effectiveness (OEE) is below 80%. How should this shift be reported?
Correct answer: C - OEE is 76.00%; review required, counting first-pass good units against planned production time.
A filler has validated individual-value control limits of 498 to 502 g and customer specifications of 495 to 505 g. A new reading is 501.7 g. The measurement system is reliable, the recent time-ordered data show no special-cause signals, and release requirements are met. An operator proposes lowering the set point to compensate for this reading. What response is warranted?
Correct answer: A - Leave the setting unchanged and continue the established monitoring plan.
An insurance-claims process has three sequential reviews. Of all claims entering, 90% pass review 1 without correction. Among those first-pass successes, 95% also pass review 2 without correction; among the claims still free of correction, 96% pass review 3. Reworked claims eventually raise final acceptance to 99%. A director describes the process as '99% right the first time.' Which result correctly challenges that statement?
Correct answer: C - 82.08% rolled throughput yield; final acceptance includes claims that needed correction.
The LSSBB exam also covers these domains. Drill them in the full free practice test:
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