Lean Six Sigma Yellow Belt

Six Sigma & Lean Fundamentals

41 free practice questions with explanations

PassNova has 41 free Lean Six Sigma Yellow Belt practice questions on Six Sigma & Lean Fundamentals, each with a clear explanation. Practise them in the browser with instant feedback — 100% free, no sign-up, on any device. Updated for 2026.

Sample questions

Six Sigma & Lean Fundamentals: example questions & answers

Here are 6 example questions from this topic. Practise the full set of 41 free in the browser.

  1. The primary goal of Lean is best described as:

    • A Reducing process variation to 3.4 defects per million
    • B Increasing the number of inspection points
    • C Maximising machine utilisation regardless of demand
    • D Eliminating waste and improving flow to deliver value to the customer

    Answer: Lean focuses on eliminating waste (non-value-adding activity) and improving flow so that value moves smoothly to the customer.

  2. In a 'Six Sigma' process, how many defects per million opportunities (DPMO) are expected?

    • A 3.4 defects
    • B 66,807 defects
    • C 6 defects
    • D 233 defects

    Answer: A process operating at Six Sigma quality (with the standard 1.5 sigma shift) produces about 3.4 defects per million opportunities.

  3. In Lean thinking, an activity that the customer is willing to pay for and that changes the product or service is called:

    • A Value-adding
    • B Business-non-value-adding
    • C Necessary waste
    • D Non-value-adding

    Answer: A value-adding activity transforms the product or service in a way the customer is willing to pay for.

  4. The term 'sigma level' in Six Sigma is a measure of:

    • A The speed of a production line
    • B The number of employees on a team
    • C How much process variation fits within customer specification limits
    • D The total cost of a project

    Answer: Sigma level expresses how many standard deviations fit between the process mean and the nearest specification limit; higher sigma means fewer defects.

  5. Which of these best describes 'common-cause' variation?

    • A Variation caused only by operator mistakes
    • B Variation that can never be reduced
    • C Variation from a one-off, unusual event
    • D The natural, inherent variation always present in a stable process

    Answer: Common-cause variation is the routine, inherent variability of a stable process, as opposed to special-cause variation from specific identifiable events.

  6. The main purpose of a kaizen event is to:

    • A Increase inventory to buffer against demand
    • B Audit the company's finances
    • C Conduct a rapid, focused improvement on a specific process over a short period
    • D Replace all factory equipment at once

    Answer: A kaizen event is a short, focused, team-based effort to rapidly improve a targeted process or area.

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