Free ASQ Certified Six Sigma Yellow Belt Sample Questions

Correct answer: A — Preventing or immediately flagging human errors before a defect can occur

• A. This is correct because poka-yoke, or mistake-proofing, is designed to make a human error either physically impossible or immediately obvious, stopping a defect before it happens.
• B. Calculating a sigma level is a Six Sigma statistical measurement activity and has no relationship to error-proofing a process step.
• C. Scheduling maintenance intervals addresses equipment reliability, which is a different concern from preventing operator mistakes.
• D. Recording cycle time for control charts is a data-collection activity used for statistical monitoring, not a mistake-proofing mechanism.

Correct answer: A — True

• A. This is true because reducing variation so process output reliably falls within specification limits is the central goal that defines the Six Sigma methodology.
• B. This is false because the statement accurately describes Six Sigma's core purpose; variation reduction is the defining objective of the methodology, not a secondary concern.

Correct answer: A — Reduced variation making the deployment process more predictable and reliable

• A. This is correct because a sharp drop in standard deviation means the deployment time now clusters much more tightly around its average, which is a direct illustration of reduced variation.
• B. This is incorrect because the scenario describes a change in the consistency of deployment time, not a stated increase in how many deployments occur per day.
• C. This is incorrect because the scenario attributes the improvement to root-cause analysis, not to adding more people to the team.
• D. This is incorrect because the scenario describes addressing root causes within the existing process, not a wholesale replacement of the deployment tool.

Correct answer: A — Self-managed team

• A. A self-managed team is granted authority over its own scheduling, work assignments, and process decisions, which is exactly the autonomy described.
• B. A cross-functional team is defined by drawing members from multiple departments to address a shared problem, not by having authority over its own daily work.
• C. A continuous improvement team focuses on ongoing incremental process gains in a work area but typically still reports to a supervisor for daily direction.
• D. An ad hoc task force is formed temporarily to resolve a specific issue and usually still answers to a sponsor rather than managing itself.

Correct answer: A — True

• A. This is accurate because norming follows storming, and it is characterized by the team resolving earlier friction and settling into shared expectations and working practices.
• B. This is inaccurate because norming does in fact follow the conflict of storming and is defined by the team establishing agreed ways of working, matching the statement.

Correct answer: B — Both back projects, but the sponsor usually funds one project while the champion selects projects and clears obstacles.

• A. Neither role is expected to personally perform statistical data collection; both operate at a management or executive level rather than doing hands-on analysis.
• B. This is correct. Both roles provide organizational backing, but funding and authorizing a specific project is typically associated with the sponsor, while identifying and selecting projects and removing roadblocks is typically associated with the champion.
• C. Neither role requires a specific belt certification; both are management-level positions defined by their organizational responsibilities, not by Six Sigma training level.
• D. Training new team members on quality tools is not a defining duty of either role, which instead focus on authorization, funding, and organizational support.

Correct answer: C — Trained in Six Sigma methods, applying them part-time to lead smaller projects or assist Black Belts.

• A. Training at this level covers DMAIC statistical methods as well as Lean tools, not Lean techniques alone.
• B. Setting enterprise-wide deployment strategy and budget describes a Master Black Belt or executive function, not this level of certification.
• C. This is correct. Training in Six Sigma methods that is applied part-time, either leading smaller projects or supporting larger Black Belt-led ones, matches this level of certification.
• D. Approving project charters is a sponsor or champion responsibility, not something tied to this certification level.

Correct answer: B — False

• A. This is incorrect because prevention costs, such as training and quality planning, are part of the cost of good quality, not COPQ.
• B. This statement is false because COPQ consists of internal and external failure costs, not prevention costs; prevention and appraisal spending is intended to avoid poor quality, so it falls outside COPQ.

Correct answer: A — A bar chart showing the frequency distribution of continuous data

• A. This is correct because a histogram uses adjacent bars to show how often values fall into different ranges, revealing the shape and spread of a continuous data set.
• B. This is incorrect because plotting data points in the order collected describes a run chart, not a histogram.
• C. This is incorrect because ranking categories from most to least frequent describes a Pareto chart, which orders discrete categories rather than showing a distribution shape.
• D. This is incorrect because sorting possible causes into categories around one effect describes a fishbone diagram, not a distribution of measured data.

Correct answer: A — Check-in time must be completed in 5 minutes or less for at least 95 percent of guests

• A. This is a properly translated CTQ because it turns the vague customer statement into a specific, measurable target with a time limit and a percentage threshold that can be tracked and improved.
• B. Friendliness is a desirable trait but is not measurable or specific, so it cannot function as a CTQ characteristic for the speed concern the customer raised.
• C. Redecorating the lobby addresses appearance, not the customer's stated concern about check-in speed, so it does not reflect the correct translation of this VOC statement.
• D. A complimentary drink is a service perk unrelated to check-in speed and provides no measurable target tied to the customer's actual comment.

Correct answer: A — A high-level view showing five to seven major process steps, not a detailed step-by-step procedure

• A. The Process element of a SIPOC diagram is meant to be a high-level view, typically five to seven major steps, giving a broad picture rather than a granular procedure.
• B. Listing every valve setting and calibration value is far too granular for a SIPOC diagram, which intentionally avoids that level of engineering detail.
• C. A keystroke-level work instruction is a detailed operational document, not the high-level process view that SIPOC is designed to capture.
• D. A complete financial audit trail is a bookkeeping record and has no relationship to the high-level process mapping purpose of SIPOC.

Correct answer: A — Matrix diagram

• A. This is correct because a matrix diagram is built to show the relationship, including strength, between two sets of factors, which is exactly what the team needs to compare causes against outputs.
• B. This is incorrect because a Gantt chart displays task timing on a schedule, which has no way to represent relationship strength between causes and outputs.
• C. This is incorrect because a work breakdown structure organizes project tasks into a hierarchy, which does not capture relationships between causes and process outputs.
• D. This is incorrect because an affinity diagram sorts ideas into thematic groups, which does not show the strength of relationships between two distinct sets of factors.

Correct answers: A, B, C — Affinity diagram; Activity network diagram; Matrix diagram

• A. This is correct because the affinity diagram, which organizes brainstormed ideas into natural groupings, is one of the seven management and planning tools.
• B. This is correct because the activity network diagram, used to sequence tasks and identify the critical path, is one of the seven management and planning tools.
• C. This is correct because the matrix diagram, used to show relationships between two or more sets of factors, is one of the seven management and planning tools.
• D. This is incorrect because a control chart is one of the basic statistical process control tools used to monitor variation over time, not one of the seven management and planning tools.
• E. This is incorrect because a Gantt chart is a scheduling tool for tracking task dates on a timeline; it is a common project tool but is not classified among the seven management and planning tools.
• F. This is incorrect because a cause-and-effect (fishbone) diagram is one of the seven basic quality tools used for root cause analysis, not one of the seven management and planning tools.

Correct answer: A — Mode

• A. The mode is correct because it is defined as the value or values that appear with the highest frequency in the data set.
• B. The mean is incorrect here because it is the arithmetic average of the values, not the most frequently occurring one.
• C. The range is incorrect here because it describes the spread between the highest and lowest values, not frequency of occurrence.
• D. Variance is incorrect here because it quantifies dispersion around the mean rather than identifying the most common value.

Correct answer: A — Mode

• A. The mode is correct because it identifies the most frequently occurring category, which works for non-numeric labels like defect type where arithmetic operations do not apply.
• B. The mean is incorrect here because it requires summing values and dividing by a count, which cannot be performed on category labels such as scratch or dent.
• C. The median is incorrect here because it requires the data to be ordered along a numeric or ranked scale, which does not naturally apply to unordered defect categories.
• D. Standard deviation is incorrect here because it measures numeric spread around a mean, which cannot be calculated for categorical defect labels.

Correct answer: A — Repeatability, because only the equipment's own consistency is being tested

• A. This is correct. Repeating measurements of the same part with the same gauge and same operator, without other changes, isolates equipment variation, which is repeatability.
• B. Reproducibility requires comparing readings across different operators, but this scenario uses only one technician and one gauge, so appraiser variation is not what is being isolated.
• C. Linearity requires comparing bias across multiple reference values spanning the gauge's range, but this scenario uses a single reference block, so it does not test linearity.
• D. Bias would require comparing the average of the readings to the block's certified true value, but the scenario only describes checking how tightly the readings cluster, not comparing to a reference value.

Correct answer: B — False

• A. This is incorrect. Accuracy and precision describe different properties: accuracy is closeness to the true value, while precision is closeness of repeated measurements to each other, so the statement is false.
• B. This is correct. Accuracy and precision are distinct MSA concepts; a measurement system can be precise without being accurate, or accurate without being precise.

Correct answer: A — Interview

• A. An interview is a direct, often one-on-one conversation used to explore an individual's detailed opinions or experiences in depth.
• B. A check sheet is a tally form for counting event occurrences, not a conversational technique for gathering detailed opinions.
• C. A checklist verifies that steps or items were completed, which does not involve an in-depth conversation.
• D. A survey typically reaches many respondents with fixed questions rather than one in-depth individual conversation.

Correct answer: A — True

• A. Cycle time recorded in seconds is a numeric measurement that can be averaged and statistically analyzed, which is the definition of quantitative data.
• B. This statement is not false; recording cycle time in seconds produces numeric values, which fits the definition of quantitative rather than qualitative data.

Correct answer: A — Sort — remove items that are not needed for current operations from the workstation

• A. Removing broken tools, outdated forms, and obsolete parts that are no longer needed is the sort step, and it must happen before the remaining items can be organized.
• B. Cleaning addresses dirt and disorder on surfaces, but it does not address the presence of unneeded items still occupying space in the workstation.
• C. Writing a standard checklist for how the area should be maintained comes after the workstation has already been sorted and organized, not before.
• D. Scheduling audits to sustain the system only makes sense once sorting, organizing, and cleaning have already been completed.

Correct answer: A — Current controls are unlikely to catch the failure before it reaches the customer

• A. Detection is scaled so a high number means poor detectability, meaning existing controls are unlikely to catch the failure before the customer is affected.
• B. Controls that reliably catch a failure correspond to a low detection rating, not a high one.
• C. How frequently a failure occurs is captured by the occurrence rating, not by detection.
• D. How catastrophic the effect would be on the customer is captured by the severity rating, not by detection.

Correct answer: A — True

• A. Force-field analysis is specifically structured to list driving forces that support a proposed change alongside restraining forces that oppose it, so this statement matches how the tool works.
• B. This statement accurately describes force-field analysis, so marking it as not matching the tool would be incorrect.

Correct answers: A, C, E — It uses a structured series of disciplines that ends with recognizing the team's contribution; It includes an interim containment step to protect customers before the root cause is found; It requires the team to verify that a corrective action actually eliminates the root cause

• A. The 8D process is a defined sequence of eight disciplines, and the final discipline formally recognizes the team's effort once the problem has been resolved.
• B. 8D is a structured investigation and corrective action process, not a tool that relies exclusively on control charts, which are used for ongoing statistical monitoring instead.
• C. 8D includes an early discipline where the team puts an interim containment action in place specifically to protect customers while the root cause investigation continues.
• D. 8D is a standalone corrective action methodology that can be applied to a problem directly; it does not require the 5 Whys to have already resolved the issue beforehand.
• E. 8D includes a discipline where the team must verify that the chosen corrective action truly removes the root cause before it is considered complete.
• F. 8D is built around a cross-functional team from the very first discipline, so it depends on that involvement rather than replacing the need for it.

Correct answer: A — A permanent action removes the root cause so the problem cannot recur, while interim action only limits effects for now

• A. Permanent action targets and removes the underlying root cause so the problem is prevented from recurring, whereas interim action only holds the symptom in check until that permanent fix is ready.
• B. Both actions occur after the problem has been identified; the permanent action follows cause analysis, not the reverse order stated here.
• C. Permanent action is not optional; it is required to eliminate recurrence, and successful containment does not remove the need for a lasting fix.
• D. Both interim and permanent actions are determined by the improvement team based on analysis, not assigned based on who selects them.

Correct answer: A — Validation confirming the solution's effectiveness on the defect rate over an ongoing period

• A. Without checking whether the defect rate actually improved after the fix, the team has skipped validation, the step that confirms the solution truly eliminated or reduced the problem.
• B. The scenario states the team already identified and fixed a specific defect, implying a problem statement existed to guide that work.
• C. Containment addresses the interim period before a fix is in place; the scenario is about the missing step after the fix was already implemented.
• D. The scenario does not indicate the root cause step was skipped; it specifically describes a missing check on the outcome after the new inspection step was added.

Correct answer: A — Shut-out (control) type

• A. Correct — a shut-out (control) type poka-yoke physically stops the process as soon as it detects an error, preventing the defect from continuing downstream.
• B. Incorrect — an attention (warning) type only signals the error with a light, sound, or alert; it does not stop the machine on its own.
• C. Incorrect — fixed-value describes a counting-based detection approach, not the machine's stop-versus-alert response category.
• D. Incorrect — motion-step describes sequencing verification, not whether the device stops the process or merely warns about the error.

Correct answer: A — To proactively identify potential failure modes and rank which ones need action first

• A. Correct — FMEA systematically identifies potential failure modes for a process and ranks them by severity, occurrence, and detection so the highest-risk ones are addressed first.
• B. Incorrect — calculating the cost of a defect that already reached the customer is a reactive cost-of-quality calculation, not what FMEA is used for.
• C. Incorrect — scheduling routine maintenance is a planning task; it is not the structured risk-ranking analysis that FMEA performs.
• D. Incorrect — logging who performed each step is a traceability record, not the proactive failure-mode analysis that FMEA provides.

Correct answers: A, B, C — A skewed shape can make the mean a misleading measure of typical performance; A bimodal shape can reveal that unstratified subgroups are mixed in the sample; Distribution shape can indicate whether common statistical tools assuming a bell curve are appropriate

• A. This is correct because in a skewed dataset the mean is pulled toward the tail, so it may not represent where most of the data actually falls.
• B. This is correct because a bimodal shape often signals that two different sources of variation, such as two shifts or machines, have been combined without separating them for analysis.
• C. This is correct because many statistical methods assume normally distributed data, so recognizing a non-normal shape helps a team choose appropriate analysis techniques.
• D. This is incorrect because distribution shape only points to patterns worth investigating; it does not by itself identify the specific root cause behind those patterns.
• E. This is incorrect because distribution shape is directly relevant to interpreting control limits and capability indices, many of which assume a particular underlying shape such as normality.

Correct answer: B — False

• A. This is incorrect because special cause variation comes from an identifiable, non-routine factor and is not part of a stable process's expected behavior.
• B. This is correct because special cause variation signals something outside the normal process, such as a broken tool or material change, and warrants investigation to find and address the source.

Correct answer: A — Scatter diagram

• A. A scatter diagram plots paired data points for two variables, letting a team visually judge whether a relationship appears before computing r.
• B. A control chart tracks a single variable over time to detect special-cause variation, not the relationship between two variables.
• C. A Pareto chart ranks categories of problems by frequency and does not display the pairing of two numerical variables.
• D. A fishbone diagram organizes potential root causes of a problem and is not used to visualize correlation between variables.

Correct answer: A — A Type II error, because a real improvement went undetected by the test

• A Type II error, because a real improvement went undetected by the test. This is correct. The setting truly reduces cycle time, meaning the null hypothesis is false, yet the test failed to reject it, which is a Type II error.
• A Type I error, because a true null hypothesis was incorrectly rejected. A Type I error requires rejecting a true null hypothesis, but here the null was not rejected at all.
• A confidence interval error, because the interval was set too narrow. The scenario does not describe a confidence interval calculation; it describes a hypothesis test decision.
• A control limit error, because the process was already out of control. Control limits relate to control charts, a different analysis tool not referenced in this hypothesis test scenario.

Correct answer: A — Three to five days

• A. This is correct. Kaizen events are commonly designed as focused workshops lasting roughly three to five days to achieve a targeted improvement.
• B. This is incorrect. A single day is generally too short to complete the planning, analysis, and implementation steps typical of a kaizen event.
• C. This is incorrect. Two to three months is far longer than the short, rapid-improvement timeframe that defines a kaizen event.
• D. This is incorrect. An entire fiscal year describes an ongoing improvement program, not the compressed, short-term nature of a kaizen event.

Correct answer: A — Cost-benefit analysis

• A. This is correct. Comparing each option's implementation cost against its projected savings to choose between solutions is exactly what a cost-benefit analysis is designed to do.
• B. This is incorrect. A kaizen blitz is a short, focused improvement workshop, not a financial comparison of competing solutions' costs and savings.
• C. This is incorrect. The plan-do-check-act cycle guides testing and rolling out a single change; it does not itself compare the financial costs and savings of two options.
• D. This is incorrect. A fishbone diagram is used to identify potential causes of a problem, not to compare the projected costs and savings of proposed fixes.

Correct answer: A — To give an operator step-by-step, task-level directions for a specific job

• A. This is correct because a work instruction provides detailed, task-specific steps so that any trained operator performs the job the same way each time, reducing process variation.
• B. This is incorrect because organizational mission and values belong in high-level corporate documents, not in a task-level work instruction.
• C. This is incorrect because budget figures are a financial planning matter and have no place in a document meant to guide hands-on task execution.
• D. This is incorrect because a complaint log is a separate quality record, not a step-by-step guide for performing a task.

Correct answer: A — They standardize how tasks are performed, reducing operator-to-operator variation

• A. This is correct because standardized, documented steps mean every operator performs the task the same way, which limits the variation that control charts are designed to detect and helps preserve project gains.
• B. This is incorrect because standardized work complements control charts rather than replacing the ongoing statistical monitoring a control plan requires.
• C. This is incorrect because internal documentation has no authority over an external supplier's formulation decisions.
• D. This is incorrect because a written work instruction or SOP is a human-readable document; it does not itself automate machine settings.