Six Sigma LSSYB Practice Test Questions, Exam Dumps

Practice Exams:

View All

LSSYB Six Sigma Practice Test Questions and Exam Dumps

Question 1

When a process has proven itself to function at a Six Sigma level, this means there are fewer than how many defects per million opportunities?

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

Answer: C

Explanation:
Six Sigma is a data-driven methodology used to improve processes by reducing variability and defects. The term "Six Sigma" comes from statistics and refers to processes that operate with high precision. In practical terms, a process that performs at a Six Sigma level is expected to produce no more than 3.4 defects per million opportunities (DPMO).

To understand where this number comes from, consider the following:

The "sigma level" is a way of measuring how much a process deviates from perfection. A process that operates at "Six Sigma" quality means it is very close to being defect-free. Statistically, Six Sigma corresponds to a process that has 6 standard deviations (sigmas) between the process mean and the nearest specification limit.

Without considering shift, a true six sigma process (in a perfect distribution) would theoretically have 0.002 defects per million opportunities. However, in real-world applications, processes are assumed to shift over time (typically by ±1.5 sigma), which leads to a practical calculation of 3.4 defects per million opportunities.

This is the standard benchmark that Six Sigma practitioners use. It accounts for natural variation and system drift while still maintaining a high level of quality. It is applied across industries, from manufacturing to healthcare, to reduce errors and improve customer satisfaction.

Now, looking at the choices:

A (1.7): This is not the standard Six Sigma DPMO and may be confused with a different sigma level.
B (2.6): Also not correct. This level of defects would suggest a process performing between Five Sigma and Six Sigma.
C (3.4): Correct. This is the widely accepted defect rate for a process operating at a Six Sigma level with the standard 1.5 sigma shift.
D (10): This is far too many defects to qualify as Six Sigma performance.

In summary, Six Sigma performance is defined by achieving no more than 3.4 defects per million opportunities, which makes C the correct answer.

Question 2

Six Sigma refers to a process whose output has at least 95% of its data points within 6 Standard Deviations from the Mean.

A. True
B. False

Answer: B

Explanation:

The statement provided in the question misrepresents the actual meaning and statistical basis of Six Sigma. While it does relate to standard deviations and process variation, the claim that it captures only 95% of data points within six standard deviations from the mean is incorrect.

Let’s explore the core principles behind Six Sigma and clarify the misunderstanding.

What is Six Sigma?

Six Sigma is a quality management methodology aimed at improving processes by identifying and eliminating defects or variations. It is both a statistical concept and a management philosophy focused on continuous improvement. The term "Six Sigma" is derived from statistics, where "sigma" (σ) represents the standard deviation, a measure of variability in a data set.

Statistical Definition:

In a normally distributed process, if a process is operating at Six Sigma quality, it means that the process produces no more than 3.4 defects per million opportunities (DPMO). This level of quality corresponds to a process whose output falls within six standard deviations (σ) on either side of the process mean — accounting for a total of 12σ from one end to the other.

In pure statistical terms (assuming no shift in the process mean), 99.99966% of the data points fall within ±6σ from the mean. That is far greater than 95%, which is the range captured within approximately ±2σ in a standard normal distribution.

Here is a breakdown of how much data falls within standard deviation ranges in a normal distribution:

±1σ ≈ 68.27% of data
±2σ ≈ 95.45% of data
±3σ ≈ 99.73% of data
±6σ ≈ 99.99966% of data

Clearly, 95% falls within approximately ±2 standard deviations, not ±6. Thus, suggesting that Six Sigma refers to a process where 95% of outputs fall within six standard deviations is statistically incorrect and significantly underrepresents the level of control implied by Six Sigma.

Accounting for Process Shift:

The original Six Sigma model (as proposed by Motorola and later refined by others like GE) also incorporates a 1.5σ shift to account for long-term process variation. Even with this shift, the defect rate remains impressively low at 3.4 defects per million.

Summary:

Six Sigma does not refer to 95% of data within ±6σ.
It actually refers to 99.99966% of data within that range (or 3.4 DPMO with a 1.5σ shift).
The statement is therefore false.

Hence, the correct answer is B.

Question 3

A training program costs $3,000, and the project requires an initial investment of $12,000. If the project begins generating monthly savings of $1,800 after 3 months,

What is the payback period in months (ignoring taxes and financing costs)?

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

Answer: C

Explanation:
To calculate the payback period, we need to determine how long it will take for the project's savings to equal its total upfront costs. Here's how we approach it step by step:

Step 1: Identify the total initial cost
The total upfront cost is the sum of the training cost and the project investment:

Training cost = $3,000
Initial investment = $12,000
Total cost = $3,000 + $12,000 = $15,000

Step 2: Determine when savings begin
According to the question, the project starts saving $1,800 per month starting after 3 months. So, there is no savings for the first 3 months.

Step 3: Calculate payback after savings begin
From month 4 onward, the project saves $1,800 per month. We now need to find out how many months of savings (at $1,800 per month) it will take to recover the full $15,000.

Let x be the number of months of savings required:
$1,800 × x = $15,000
x = $15,000 ÷ $1,800
x = 8.333... months

So, it takes 8.33 months of actual savings to recover the $15,000.

Step 4: Add the 3 months of delay
Because savings begin after 3 months, the total payback period is:
3 months (waiting) + 8.33 months (recovering cost) = 11.33 months

Therefore, the payback period is 11.33 months, making the correct answer C.

Question 4

The ROI for a project is a measurement metric that stands for Return on Investment and is one of the methods used to measure the success of a Lean Six Sigma project.

A. True
B. False

Answer: A

Explanation:

The statement provided is accurate: ROI, which stands for Return on Investment, is indeed a commonly used metric for evaluating the success of a Lean Six Sigma project. It reflects the financial return relative to the investment made, and it provides tangible evidence of a project’s impact on organizational performance.

Understanding ROI:

ROI is calculated using the formula:

ROI = (Net Benefit or Gain from Investment – Cost of Investment) / Cost of Investment

This metric helps businesses determine how effective a particular project has been in generating profit or savings relative to the resources spent. In the context of Lean Six Sigma, the "investment" typically includes time, labor, software, training, and implementation costs, while the "return" could be in the form of cost savings, improved productivity, increased customer satisfaction, or reduced cycle time.

Lean Six Sigma and ROI:

Lean Six Sigma is a data-driven methodology aimed at improving quality and efficiency by reducing variation (Six Sigma) and eliminating waste (Lean). While its core tools focus on statistical analysis and process improvement, its overarching goal is to deliver measurable, financially beneficial outcomes.

To ensure that a Lean Six Sigma project is aligned with business goals, organizations often tie projects to key performance indicators (KPIs) — ROI being one of the most prominent. In fact, ROI is frequently used during the project selection and prioritization phase, where companies choose to invest in projects that promise the highest potential return.

Additionally, during the Control phase of the DMAIC (Define, Measure, Analyze, Improve, Control) cycle, ROI is reviewed to confirm that the expected benefits were realized and that the project justified its resource allocation. This helps drive a culture of accountability and continuous improvement.

Other Metrics for Measuring Lean Six Sigma Success:

While ROI is a key financial metric, it is typically considered alongside other success measures such as:

Defect reduction rates
Cycle time reduction
Customer satisfaction improvements (e.g., via NPS or surveys)
Cost savings or cost avoidance
Productivity gains
Process capability improvements (e.g., Cp, Cpk)

However, none of these negate the fact that ROI is a core financial benchmark for justifying and validating the success of process improvement projects.

Given that ROI quantifies the financial impact of a Lean Six Sigma initiative and helps assess whether the project met its intended objectives from a cost-benefit standpoint, it is indeed a valid and commonly used success metric. Therefore, the statement is correct.

The correct answer is A.

Question 5

In the DMAIC methodology used for problem solving, what does the letter "M" stand for in Define, ___, Analyze, Improve, and Control?

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

Answer: B

Explanation:
DMAIC is a structured, data-driven methodology used primarily in Six Sigma for improving existing processes. Each letter in DMAIC represents a phase of the improvement process:

D – Define: Identify the problem or project goals, determine customer requirements, and outline the scope of the project.
M – Measure: Collect data on current performance, validate the measurement system, and establish baseline performance metrics.
A – Analyze: Use the measured data to identify root causes of defects or inefficiencies in the current process.
I – Improve: Develop and implement solutions to address root causes, and optimize the process based on data analysis.
C – Control: Put systems in place to sustain improvements and ensure the process continues to perform at desired levels.

In this context, the M phase focuses on measuring the current process performance using quantifiable data. This step is crucial for establishing a baseline, identifying variances, and preparing for analysis.

Option A (Manage) is incorrect because management is a general activity, not specific to the measurement of process performance.
Option C (Memorize) is irrelevant in the context of data-driven process improvement.
Option D (Manipulate) does not reflect the purpose of the M phase, which is about objectively capturing data, not altering it.

Thus, the correct term that the "M" in DMAIC stands for is Measure, making the correct answer B.

Question 6

Voice of the Customer is a Lean Six Sigma technique to determine the ___________ attributes of a product or service.

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

Answer: C

Explanation:

The Voice of the Customer (VoC) is a foundational technique in Lean Six Sigma that helps organizations capture customers' expectations, preferences, and requirements. The correct term that completes the sentence is Critical-to-Quality (CTQ), making C the right answer.

Understanding Voice of the Customer (VoC):

Voice of the Customer refers to the process of gathering and analyzing customer feedback to understand what customers value in a product or service. This input is essential in designing, improving, and delivering offerings that meet or exceed customer expectations. The technique involves using surveys, interviews, focus groups, customer complaints, observations, and market research to capture detailed information about what customers truly need.

However, simply knowing what the customer says isn’t enough. That feedback needs to be translated into measurable, actionable items—this is where CTQs come into play.

What Are Critical-to-Quality (CTQ) Attributes?

CTQs are the key measurable characteristics of a product or service that must be met to satisfy the customer. They are derived from VoC data and help the business understand which features, specifications, or performance metrics are most important to the end user. CTQs can relate to:

Performance (e.g., speed, accuracy)
Reliability (e.g., defect rate)
Usability (e.g., user interface simplicity)
Cost-effectiveness
Aesthetic appeal (in certain products)

For example, if a VoC analysis for a mobile app reveals that customers want it to load in under 2 seconds, that becomes a CTQ metric. If the app exceeds this time, it may lead to user dissatisfaction.

CTQs in the Lean Six Sigma Process:

In the Define phase of the DMAIC cycle, teams use the VoC to identify what matters most to the customer. These are then translated into CTQs to guide process improvements. Tools like CTQ Trees are often used to break down broad customer requirements into specific, quantifiable performance indicators.

Why Not the Other Options?

A. Desirable: While customer desires are important, they are not as precisely defined or measurable as CTQs. Desirable features may be nice-to-have but aren’t necessarily critical.
B. Beneficial: This is a vague term. All customer-driven attributes could be considered beneficial, but again, it lacks the specificity and measurable nature of CTQs.
D. Preferred: This term suggests a subjective preference rather than an essential requirement. Preferences can vary widely and may not be crucial for satisfaction.

The purpose of VoC in Lean Six Sigma is to convert customer feedback into specific, actionable, and measurable requirements—what we call Critical-to-Quality (CTQ) attributes. These attributes then drive process improvement efforts to ensure the product or service consistently meets customer expectations.

Therefore, the correct answer is C.

Question 7

Benefits and working conditions would be primarily the concern of which of the following?

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

Answer: B

Explanation:
In quality management and continuous improvement frameworks, "Voice of the..." concepts are used to represent the different perspectives that influence or are influenced by a process. Here's what each typically represents:

Voice of the Customer (VoC) focuses on external customer needs, expectations, and preferences. This voice is concerned with product features, quality, timeliness, and customer satisfaction.
Voice of the Employee (VoE) reflects the concerns, feedback, and needs of employees within an organization. This includes areas like benefits, working conditions, job satisfaction, engagement, and safety.
Voice of the Business (VoB) captures the goals and priorities of the business such as profitability, growth, efficiency, and market position. It often aligns with financial performance and strategic direction.
Voice of the Process (VoP) deals with the data and performance metrics coming directly from a process. It includes things like defect rates, cycle times, and capacity.

In this case, benefits and working conditions are directly related to employee well-being and satisfaction. These are internal concerns that affect workforce morale, productivity, and retention. As such, these topics are squarely within the realm of the Voice of the Employee.

Option A, Voice of the Customer, is incorrect because while customers may care indirectly about employee conditions (e.g., how it affects service), they are not the primary focus when it comes to internal benefits.
Option C, Voice of the Business, is more aligned with profitability and strategy, not specifically with employee perks or environment.
Option D, Voice of the Process, is related to operational data, not human resource concerns.

Therefore, the correct answer is B.

Question 8

In the expression Y = f(Xn) Y, the output, is the ___________ variable and Xn, the inputs, are the __________ variables.

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

Answer: D

Explanation:

The expression Y = f(Xn) is a fundamental concept in Lean Six Sigma and statistical modeling, where Y represents the output or outcome of a process, and Xn represents the input variables or factors that influence that outcome. This expression can be read as "Y is a function of X," meaning the output depends on the inputs.

This leads us to the correct classification of variables:

Y (the output) is the dependent variable.
Xn (the inputs) are the independent variables.

Let’s explore why this classification holds and how it fits into Lean Six Sigma methodology.

Understanding the Relationship:

In any process improvement or statistical modeling effort, understanding the relationship between variables is crucial. The formula Y = f(X) is used to represent that the output (Y) is determined by one or more inputs (Xn). The function f describes how the inputs are mathematically or logically related to the output.

This aligns with the goal of Lean Six Sigma, which is to improve outputs (Y) by identifying and controlling the key inputs (Xn). These inputs are also often referred to as process variables, factors, or drivers.

Why is Y the dependent variable?

Because Y changes in response to or depends on changes in the input variables (Xn). For example, in a process to bake cookies, the quality of the final cookie (Y) depends on inputs like baking time, oven temperature, and ingredient measurements (Xn). If any of those inputs are changed, the output (the cookie’s quality) will also change.

Why are Xn the independent variables?

Each X is considered independent because it can be adjusted or varied to observe its effect on the output. These variables are what the team manipulates or analyzes in experiments or process improvement efforts. Independent variables are not influenced by Y but rather influence Y.

Lean Six Sigma Application:

In the Measure, Analyze, and Improve phases of DMAIC, teams use the Y = f(X) framework to:

Identify the Critical Xs (i.e., which input variables significantly affect the output Y).
Quantify how changes in X impact Y.
Optimize the values of X to achieve a desired Y.

Summary of Incorrect Options:

A. Independent, dependent: This reverses the relationship; it's incorrect because Y is not independent—it depends on X.
B. Individual, multiple: While there may be multiple X variables, this terminology doesn’t explain their statistical role.
C. Sole, multiple: Also fails to capture the statistical dependency.

The correct interpretation of the expression Y = f(Xn) is that Y is the dependent variable because it relies on or is affected by the inputs, and Xn are the independent variables because they determine the behavior or outcome of Y.

Therefore, the correct answer is D.

Question 9

When we assess the Voice of the Customer we are attempting to determine the gaps in our processes between “what is” and __________________.

A. “What isn’t”
B. “What will make money”
C. “What will cost less”
D. “What should be”

Answer: D

Explanation:
The Voice of the Customer (VoC) refers to the process of capturing customers’ expectations, preferences, and aversions. It is a fundamental aspect of quality management and continuous improvement methodologies like Six Sigma and Lean. The VoC helps organizations align their products, services, and processes with customer desires.

When assessing the Voice of the Customer, organizations are essentially trying to understand the gaps between the current state (“what is”) and the ideal state (“what should be”) from the customer’s perspective. This analysis is essential to prioritize improvement projects and ensure the outputs meet or exceed customer expectations.

Let’s examine the answer choices:

A. “What isn’t” – This is too vague and does not define a target or desired state. It merely implies absence rather than a goal.
B. “What will make money” – While financial gain is a business goal, VoC is primarily focused on customer satisfaction, not directly on profit. Profitability may result from meeting VoC, but it’s not the target of VoC assessment.
C. “What will cost less” – Cost reduction is a business efficiency goal. VoC is about identifying customer needs, not internal cost-cutting.
D. “What should be” – This is the most accurate description of the VoC goal. The ideal state reflects what the customer actually wants or expects. Comparing this to the current state (what is) reveals the gap, which informs improvement priorities.

For example, if customers expect product delivery in 2 days (what should be), but current delivery takes 5 days (what is), then VoC analysis has identified a gap. Organizations can then take action to improve delivery time to align with customer expectations.

Understanding the difference between "what is" and "what should be" enables businesses to better satisfy their customers, remain competitive, and improve quality. This makes D the correct answer.

Question 10

Which of the following would likely not be a CTQ (Critical-to-Quality) for the purchase of a product?

A. Functionality
B. Durability
C. Dependability
D. None

Answer: D

Explanation:

In Lean Six Sigma, a CTQ (Critical-to-Quality) characteristic refers to any attribute or feature of a product or service that is essential to meeting customer expectations. CTQs are derived from the Voice of the Customer (VoC) and help businesses focus on what truly matters to end users. These attributes are measurable, actionable, and critical in ensuring customer satisfaction and product or service quality.

The question asks which of the listed options would not likely be considered a CTQ in the context of purchasing a product. The options provided are:

Functionality
Durability
Dependability
None

Let’s examine each of the three main options before evaluating the choice “None.”

Functionality: This refers to whether the product performs the tasks it is intended to perform. For example, a smartphone must be able to make calls, access apps, and browse the internet. Functionality is almost always one of the most critical attributes customers expect in any product. If a product lacks the core functionality for which it was purchased, it would be deemed defective or substandard. Therefore, functionality is very much a CTQ.

Durability: This reflects the product's ability to last over time under normal use conditions. A durable product is one that resists wear and tear, does not easily break down, and continues to perform well over its expected lifespan. Customers often factor durability into their purchasing decisions, especially for high-value or frequently used items like electronics, appliances, or tools. Thus, durability is also a CTQ.

Dependability: This is the attribute related to reliability and consistent performance. A dependable product performs as expected without failure. Dependability is critical for customer satisfaction, especially for items that are used regularly or play essential roles, such as medical equipment, transportation devices, or communication tools. Like the others, dependability is a clear CTQ.

So what about option D – “None”?

Choosing “None” implies that all of the listed options (A, B, and C) would be considered CTQs for most products. And that is absolutely correct. Each one—functionality, durability, and dependability—is an attribute that customers commonly care about and are willing to evaluate when making purchasing decisions. These features are often non-negotiable for customers and are vital for ensuring the product meets minimum quality expectations.

Therefore, since all of the options listed are typically CTQs, the answer to the question "Which would not be a CTQ?" must be none—because none of them fall outside the category of Critical-to-Quality attributes.

Functionality, durability, and dependability are all important and measurable attributes that customers expect from products. They are consistently used in defining CTQs during Lean Six Sigma projects focused on product design or improvement. Therefore, the correct response is that none of the listed attributes would be excluded from being a CTQ.

The correct answer is D.