Six Sigma LSSYB Exam Dumps & Practice Test Questions

Question 1:

In Six Sigma methodology, what is the maximum number of allowable defects per million opportunities for a process that is operating at Six Sigma quality?

A. 1.7
B. 2.6
C. 3.4
D. 10

Answer: C

Explanation:

Six Sigma is a well-established approach to quality control that aims to significantly minimize defects and process variability. A central concept in this methodology is the relationship between the sigma level of a process and the number of defects it produces. When a process is said to be performing at the “Six Sigma” level, it refers to an extremely high level of precision and consistency, where the process generates no more than 3.4 defects per million opportunities (DPMO).

To understand how this figure is derived, it’s important to consider the statistical foundation behind Six Sigma. In an ideal world—where a process stays perfectly centered around the mean—Six Sigma represents six standard deviations (±6σ) between the mean and the closest specification limit. This would imply a theoretical defect rate of only 0.002 DPMO, or near-perfect quality.

However, real-world processes are not perfect and often experience minor shifts over time due to natural variation. To account for this, Six Sigma calculations assume a 1.5 sigma shift in the process mean. With this adjustment, the expected defect rate increases to 3.4 defects per million opportunities—a practical benchmark that still ensures exceptionally high quality.

Now, let’s review the answer choices:

• A (1.7): This is not the standard Six Sigma defect rate. It might suggest a process performing beyond Six Sigma quality, which is rarely achievable or necessary in most industries.

• B (2.6): While closer to the correct value, it still underestimates the Six Sigma threshold.

• C (3.4): Correct. This is the widely accepted DPMO for a process performing at Six Sigma with a 1.5σ shift accounted for.

• D (10): Too high to be considered Six Sigma performance and would indicate a less controlled process.

In summary, Six Sigma signifies world-class process quality with minimal defects. A process operating at this level will produce no more than 3.4 DPMO, making Option C the correct choice.

Question 2:

Is it true that Six Sigma refers to a process in which at least 95% of all data points fall within six standard deviations of the mean?

A. True
B. False

Answer: B

Explanation:

The idea that Six Sigma represents a process with 95% of data points within six standard deviations from the mean is a misconception and statistically incorrect. To accurately assess this, one must first understand what Six Sigma actually measures in terms of process capability and data distribution.

In statistical terms, Six Sigma refers to a process where 99.99966% of all output falls within ±6 standard deviations (σ) from the process mean, assuming a normal distribution with no shift in the mean. This extremely high level of accuracy means that out of one million opportunities, only about 0.002 defects would be expected—virtually zero in most practical applications.

However, Six Sigma also incorporates the reality that processes are not perfectly stable over time. Due to long-term drift and natural variation, a 1.5σ shift is often factored in. With this shift, the estimated defect rate rises slightly, resulting in the commonly cited figure of 3.4 defects per million opportunities (DPMO).

Let’s look at how data typically distributes in a normal curve:

• ±1σ: About 68.27% of data

• ±2σ: About 95.45% of data

• ±3σ: About 99.73% of data

• ±6σ: About 99.99966% of data

From the above, it is clear that 95% of the data lies within approximately ±2σ, not ±6σ. So the statement that Six Sigma refers to 95% within ±6σ dramatically underrepresents the level of quality and control that Six Sigma actually entails.

The 95% confidence level is associated with much lower process capability, typically represented by Two Sigma or 2σ processes—not Six Sigma.

To summarize:

• Six Sigma = 99.99966% within ±6σ

• 95% = only within ±2σ

• Therefore, the statement in the question is false

The Six Sigma standard is far more rigorous than 95% compliance. It represents near-perfection in process output, making Option B (False) the correct response.

Question 3:

A company launches a project with an initial cost of $12,000 and a separate $3,000 training expense. Monthly savings of $1,800 are expected to begin in the fourth month. 

Ignoring any tax or financing implications, how many months will it take to recover the total investment?

A. 4.17
B. 8.33
C. 11.33
D. 28.28

Correct Answer: C

Explanation:

To find the payback period, we need to determine how long it will take the project to recoup the total costs through savings. The payback period is a simple financial metric that measures the time required for an investment to be recovered through cash inflows (in this case, monthly savings). Let’s walk through the calculation step by step.

Step 1: Calculate the total upfront cost.
The project involves two initial expenses:

• Training: $3,000

• Project investment: $12,000

• Total initial cost = $3,000 + $12,000 = $15,000

Step 2: Understand when savings begin.
The project does not generate any savings for the first 3 months. Starting in month 4, it begins to produce $1,800 in monthly savings.

Step 3: Determine how many months of savings are needed.
To recover the $15,000 investment through monthly savings:
Let x be the number of months of savings needed to fully recover the cost:
$1,800 × x = $15,000
x = $15,000 ÷ $1,800
x ≈ 8.33 months

Step 4: Add the initial delay.
Since the project doesn’t begin generating savings until month 4, the first 3 months are non-revenue-generating. Therefore, the total payback period becomes:
3 months (delay) + 8.33 months (savings period) = 11.33 months

This tells us that the full investment is recovered approximately 11.33 months after the project start date.

The correct answer is C. 11.33 months. This payback period calculation is valuable in assessing whether a project justifies the initial outlay, especially in Lean Six Sigma and cost-saving initiatives where ROI and breakeven time are key decision factors.

Question 4:

Is Return on Investment (ROI) considered a valid metric for measuring the success of a Lean Six Sigma project?

A. True
B. False

Correct Answer: A

Explanation:

Return on Investment (ROI) is widely recognized as a standard financial metric used to assess the effectiveness of investments, including process improvement projects such as those run under Lean Six Sigma (LSS) methodologies. The goal of LSS is to reduce waste, eliminate process variation, and deliver measurable outcomes—many of which are quantified using ROI.

What is ROI?
ROI is calculated using the formula:
ROI = (Net Gain from Investment – Investment Cost) ÷ Investment Cost
This metric indicates how much return is achieved for each dollar invested. A higher ROI implies greater effectiveness and financial justification for a project.

Why is ROI important in Lean Six Sigma?
Lean Six Sigma focuses on data-driven decision-making and aligning process improvements with strategic business goals, such as cost reduction, productivity, and quality enhancement. ROI helps stakeholders evaluate whether the results of a project were worth the effort, cost, and time invested.

• During project selection, ROI estimates help organizations prioritize initiatives that offer the highest returns.

• In the Control phase of the DMAIC cycle, actual ROI is used to validate that the project delivered the expected financial benefits.

• Post-implementation, ROI serves as a validation tool to justify continued investment in similar improvement methodologies.

Other LSS metrics include:

• Defect reduction

• Time and cycle efficiency

• Cost savings and cost avoidance

• Improved customer satisfaction (e.g., via NPS scores)

• Productivity improvements
  While these operational KPIs provide insights into process-level performance, ROI translates those gains into business value, making it a vital part of executive-level reporting.

Because ROI directly reflects how financially successful a Lean Six Sigma project has been—and supports decisions at both strategic and operational levels—it is indeed a valid and critical metric for measuring project success.
Thus, the correct answer is A. True.

Question 5:

In the structured problem-solving approach known as DMAIC, what does the “M” represent in the sequence: Define, ___, Analyze, Improve, and Control?

A. Manage
B. Measure
C. Memorize
D. Manipulate

Answer: B

Explanation:

DMAIC is a five-phase methodology widely used in Six Sigma and process improvement initiatives. The acronym stands for Define, Measure, Analyze, Improve, and Control, each of which represents a distinct phase in identifying and addressing issues in an existing process.

The “M” in DMAIC stands for Measure, which is the second phase of the methodology. This step plays a critical role in establishing a quantitative understanding of the current process performance. The aim is to collect baseline data, validate measurement systems, and define key performance indicators (KPIs) to prepare for deeper analysis later in the DMAIC cycle.

Here’s a breakdown of each phase for context:

• Define: Identify the problem, project goals, customer needs, and process boundaries.

• Measure: Gather data to establish a clear picture of current performance. This includes defining what to measure, how to measure it, and using tools such as process maps, control charts, or run charts.

• Analyze: Use the measured data to determine root causes of process inefficiencies or defects.

• Improve: Develop and test solutions to eliminate those root causes and optimize performance.

• Control: Put measures in place to ensure improvements are maintained over time.

Focusing on the Measure phase, it is essential because without accurate and relevant data, subsequent analysis could be misleading or flawed. In this phase, metrics are not only recorded but validated to ensure that they provide a reliable basis for problem-solving. It lays the foundation for data-driven decision-making in the remaining phases.

Now, examining the other options:

• A. Manage sounds plausible, but management functions are broader and do not specifically address the technical task of measurement within process improvement.

• C. Memorize has no relevance in this context, as DMAIC is concerned with objective data and analysis rather than memory.

• D. Manipulate implies changing data or variables, which is not the purpose of the Measure phase. This phase focuses solely on capturing current data, not altering it.

In conclusion, the “M” in DMAIC refers to Measure, making B the correct answer. It is a crucial step in understanding the current state of a process and preparing for meaningful, data-driven improvements.

Question 6:

Within the Lean Six Sigma methodology, the "Voice of the Customer" (VoC) is used to identify which of the following types of product or service attributes?

A. Desirable
B. Beneficial
C. Critical-to-Quality
D. Preferred

Answer: C

Explanation:

In Lean Six Sigma, the Voice of the Customer (VoC) is a pivotal tool used to understand and capture the needs, preferences, and expectations of the end users. It forms the basis for ensuring that any product or service improvement aligns directly with what matters most to customers.

The correct answer here is Critical-to-Quality (CTQ), which are the essential attributes derived from customer feedback that directly influence customer satisfaction. These are measurable characteristics of a product or service that must meet specific criteria for the customer to consider the offering acceptable or high-quality.

The VoC process gathers qualitative data through tools such as:

• Surveys and questionnaires

• Customer interviews

• Focus groups

• Observations and complaints

• Market research

After collecting the data, the next step is to translate these needs into CTQs, using tools like CTQ trees. For example, if customers say they want a “fast” service, the CTQ might be “response time < 2 seconds.”

CTQs can include elements like:

• Performance (e.g., application loading time)

• Reliability (e.g., system uptime)

• Usability (e.g., intuitive interface)

• Accuracy (e.g., error rate)

• Compliance (e.g., adherence to regulations)

Why CTQs are important:

• They create a bridge between customer expectations and engineering metrics.

• They enable teams to prioritize improvement efforts based on what drives satisfaction.

• They serve as benchmarks for designing, testing, and validating process improvements.

Now, let’s evaluate the other options:

• A. Desirable suggests nice-to-have features but doesn’t indicate necessity or performance targets. While desirable traits are helpful, they aren’t guaranteed to affect customer satisfaction as directly as CTQs.

• B. Beneficial is a vague term that lacks specificity. While CTQs are indeed beneficial, the term doesn’t capture their critical and measurable nature.

• D. Preferred reflects subjective tastes that can vary significantly. CTQs, on the other hand, are objective and universal for the defined customer segment.

In summary, VoC is used to identify CTQs, which guide improvement efforts in Lean Six Sigma by transforming customer feedback into structured, actionable quality metrics. Thus, C is the correct answer.

Question 7:

Which "Voice of..." category primarily addresses employee-related topics such as working conditions and benefits?

A. Voice of the Customer
B. Voice of the Employee
C. Voice of the Business
D. Voice of the Process

Correct Answer: B

Explanation:

In process improvement frameworks such as Lean Six Sigma, multiple “voices” are used to represent the needs and perspectives of various stakeholders and process elements. These are known as Voice of the Customer (VoC), Voice of the Employee (VoE), Voice of the Business (VoB), and Voice of the Process (VoP). Each serves a distinct role in identifying requirements, expectations, or opportunities for enhancement.

When we refer to employee-centric factors like benefits, job satisfaction, morale, and working conditions, we are directly aligning with the Voice of the Employee (VoE). VoE encompasses the feedback, insights, concerns, and needs of the organization's workforce. This may include physical workspace quality, mental health support, training opportunities, and the perceived fairness of compensation. Organizations that proactively listen to VoE are often better equipped to improve employee engagement, reduce turnover, and create a more productive culture.

Let’s contrast VoE with the other options:

• A. Voice of the Customer (VoC) captures the expectations and satisfaction levels of external customers. It focuses on product quality, service delivery, and responsiveness, but does not delve into internal HR-related issues like benefits or workplace conditions.

• C. Voice of the Business (VoB) reflects the priorities of the business itself—profitability, strategy execution, cost management, and growth targets. While VoB may influence HR budgeting, it does not directly reflect employees' day-to-day experiences or welfare.

• D. Voice of the Process (VoP) deals with objective performance data from the system or process. It includes metrics like cycle times, throughput, and defect rates. VoP tells you how efficiently the process operates but not how employees feel or what they need.

Understanding the Voice of the Employee is essential to successful organizational change. A disengaged or dissatisfied workforce can lead to process inefficiencies, high turnover, and a drop in service quality—negatively affecting both VoC and VoB. That’s why many quality initiatives include tools such as employee surveys, feedback loops, and team huddles to capture VoE.

To summarize: since working conditions and benefits directly relate to internal workforce satisfaction, they fall under Voice of the Employee, making B the correct answer.

Question 8:

In the formula Y = f(Xn), how are the variables classified in terms of dependency?

A. Independent, dependent
B. Individual, multiple
C. Sole, multiple
D. Dependent, independent

Correct Answer: D

Explanation:

The expression Y = f(Xn) is a core concept in process improvement, statistical analysis, and data-driven methodologies like Lean Six Sigma. It states that Y, the outcome or result, is a function of Xn, the inputs or contributing factors. This equation frames the idea that outputs are determined by inputs, forming the basis for analytical problem-solving and optimization.

In this formula:

• Y is the dependent variable, also referred to as the “output” or “effect.”

• Xn represents one or more independent variables—these are the “inputs” or “causes.”

This classification is fundamental in understanding how process variables interact. The dependent variable (Y) is what an organization aims to improve, control, or predict. For example, Y might represent customer satisfaction, product quality, or processing time. The independent variables (X1, X2, X3…Xn) are the factors that influence or cause changes in Y—such as training levels, raw material quality, machine settings, or temperature.

In Lean Six Sigma, the goal of the Analyze and Improve phases is to identify the “Critical Xs” (the few variables among many that most influence Y) and then optimize or control them to produce better Y outcomes. The idea is: if you control the inputs, you can control the output.

Let’s evaluate the incorrect options:

• A. Independent, dependent reverses the relationship. It inaccurately suggests that Y is independent and X is dependent, which is not the case. The output (Y) changes because of the inputs—not the other way around.

• B. Individual, multiple may loosely describe that there is one Y and potentially many Xs, but these terms don’t convey their statistical dependency, which is critical in analysis.

• C. Sole, multiple also implies a numerical relationship (one Y, many Xs), but again, it fails to express the functional dependence, which is the heart of the concept.

In conclusion, the correct answer is D: Dependent, independent—because Y is the outcome that depends on the values of the independent variables Xn. This relationship forms the backbone of predictive modeling and process improvement in Lean Six Sigma.

Question 9:

When evaluating the Voice of the Customer (VoC), what are we primarily trying to uncover by comparing the current process state to another reference point?

A. What isn’t happening in the process
B. What actions could drive higher profits
C. What changes might reduce internal costs
D. What the process ought to be delivering

Correct Answer: D

Explanation:

The concept of Voice of the Customer (VoC) is central to Six Sigma and quality improvement methodologies. It involves gathering detailed insights into what customers expect, prefer, and need from a product or service. This information becomes the cornerstone for designing or refining processes that align more closely with customer demands.

When organizations assess the VoC, they are effectively comparing the “current state” (i.e., what the process currently delivers) with the “desired future state” — in other words, what should be delivered to satisfy the customer. Therefore, the correct answer is D, because the goal is to bridge the gap between what is and what should be from the customer's viewpoint.

Let’s break down why the other options are not appropriate:

• A. "What isn’t" is too ambiguous. It doesn’t offer a defined target or performance benchmark. Quality initiatives need measurable goals, not simply the absence of something.

• B. "What will make money" addresses internal financial goals, not customer experience. While customer satisfaction may ultimately lead to profit, profit is not the immediate focus of VoC analysis.

• C. "What will cost less" relates to efficiency improvements, but VoC is about external customer expectations, not internal expense reduction.

VoC analysis often uncovers areas where customer expectations are unmet. For instance, if customers expect a product to be delivered within 48 hours (what should be), but the current average delivery time is 72 hours (what is), the gap becomes evident. Identifying and addressing such gaps helps ensure the process becomes more customer-aligned.

In Lean Six Sigma projects, VoC data is translated into Critical-to-Quality (CTQ) requirements. These CTQs define specific, measurable characteristics that must be met to satisfy customers. Therefore, VoC acts as the compass guiding process improvement toward customer-centric goals.

By consistently comparing the “what is” with “what should be,” organizations can prioritize process changes that directly enhance customer satisfaction and loyalty.

Question 10:

Which of the following characteristics is not likely to be excluded as a Critical-to-Quality (CTQ) attribute when evaluating a product purchase?

A. Functionality
B. Durability
C. Dependability
D. None of the above

Correct Answer: D

Explanation:

A Critical-to-Quality (CTQ) attribute refers to any product or service characteristic that is crucial for meeting customer expectations. CTQs are the measurable and customer-defined parameters that organizations must achieve to deliver a quality product. These often include performance, reliability, usability, and other tangible features that impact customer satisfaction.

The question here is asking: which of the given options would not be excluded as a CTQ? That is, which of these characteristics are always or usually considered CTQs in product evaluations?

Let’s evaluate each option:

• Functionality refers to the core purpose of the product—its ability to perform the intended task. For example, a smartphone must make calls, access the internet, and run applications. If the product doesn’t function correctly, it fails its most basic purpose. Thus, it’s definitely a CTQ.

• Durability pertains to how long the product can perform under normal or expected use without failure. Customers routinely consider product lifespan in purchasing decisions. Whether it's a car, a washing machine, or even packaging materials, durability is a vital CTQ.

• Dependability implies that the product works reliably and consistently. A dependable product doesn’t break down unexpectedly or produce inconsistent results. This quality is critical in industries such as healthcare, aviation, and IT, where reliability is paramount. Therefore, dependability is also a strong CTQ.

Now, what about option D, "None of the above"? This option implies that all the listed characteristics are CTQs — and that’s absolutely accurate. Functionality, durability, and dependability are universally important traits for nearly all consumer and industrial products. They directly influence user experience, product satisfaction, and brand perception.

In Lean Six Sigma, identifying CTQs through tools like CTQ Trees helps translate broad customer needs into precise, actionable performance requirements. If a feature does not meet its CTQ standard, it may trigger customer complaints, product returns, or even reputational damage.

Since all the listed options (A, B, and C) are typically classified as CTQs, the correct answer is D – none should be excluded.