six sigma questions

Select all that are components of a control plan?

Key metrics spec limits measurements mitigation actions

Select all correct responses, Hypothesis testing can help us...

Make fact-based decisions Separate special cause from noise

Stability in an MSA is the consistency of measurements of the same objects over time?

True

We can better sustain standardized work with which of the following? More than one response may apply.

5S Visual Factory

Which of the following best describe Sigma?

A measurement scale upon which improvements can be gauged

Which of the following statements is NOT correct?

a correlation of -0.9 indicates a strong positive relationship

Which of the following might review Process Performance?

a project sponsor a process owner project stakeholder

With Measurement System Analysis, we are concerned with Precision and _______ of the data to be collected.

accuracy

stability, Bias and Linearity define the __________ of a Measurement System

accuracy

Which of these is not one of the 4 stages of team development?

adorning

As we conceive and define a LEAN Six Sigma project, one of the overriding objectives we hope to accomplish is to reduce the __________

cost of poor quality

COPQ is an acronym that stands for?

cost of poor quality

A quality control function was introduced to catch defects before shipment to the customer. The cost of this quality control function is an example of:

cost related to detection

How do we summarize discrete data?

counts and proportion

CTQ is an acronym that stands for what?

critical to quality

What are some LEAN Six Sigma objectives?

customer satisfaction delivering business results achieving business targets reducing variation

Where in your SIPOC might stakeholders be represented?

customers

The only purpose of LEAN is to concentrate efforts on removing variation from a process output and lowering costs

false

When eliminating insignificant variables from a multiple linear regression model, we should remove all insignificant variables at the same time?

false

What is not a good reason for spending so much time in the Define phase?

filling out redundant templates, getting unnecessary approvals and completing administrative tasks

__________ is an analysis technique to identify, evaluate and prioritize a potential deficiency in a process so that the project team can design action plans to reduce the probability of the failure/deficiency occurring.

fmea

_________ is used to model the linear relationship between one output and two or more inputs?

multiple linear regression

The Control Plan is created following the finalization of the Improve phase and can be closed when?

never, a control plan must stay in place

Can you add standard deviations?

no

Every hypothesis test must..

have Ho and Ha have a defined alpha level

Process ________ measures how well the process performs to meet given customer specification limits?

process capability

All of the following are benefits of control plans except?

helps to analyze and eliminate potential x's

An intended outcome of using SPC should be?

process stability

an intended outcome of using SPC should be?

process stability

In 5S, the approach that deals with cleansing, repairing, and/or painting machinery or other work spaces is known as which stage?

shine

Motorola was the birthplace for the practice of?

six sigma

As part of a 5S activity tags or stickers are used to identify items in need of elimination or other categorization. This process is conducted at what stage of the 5S process?

sort

SPC is used to identify the ____ cause variation?

special

If VIF ≥ 10, there is no multicollinearity?

false

If the correlation coefficient of two variables is zero, the two variables are independent?

false

In a multiple linear regression analysis, the p-values of the insignificant predictors are the ones that are smaller than the alpha level?

false

Inferential statistics is descriptive only and does not make any generalizations beyond the data at hand?

false

Lean is only about removing waste from the enterprise?

false

One-way ANOVA (one-way analysis of variance) is a statistical method to compare variances of two or more populations?

false

Pearson's correlation coefficient measures both linear and non-linear relationship between two variables?

false

SPC on the outputs is more preferred than SPC on the inputs when implementing SPC for your process.

false

The Japanese word for waste is Sieri?

false

The essence of Six Sigma is to concentrate on removing waste (Muda) from a process while lowering costs.

false

What are some key outputs of the Define phase?

(D/U*O)*1,000,000 Where D=Defects, U=Units, O=Opportunities

What is the DPU in this example: 423 defects, 7600 units

0.056

The Cp for a process with an average of 100 and a standard deviation (within) of 12 and upper & lower specification limits of 114 and 90 would be?

0.33

What is the subgroup size when using a I-MR control chart?

1

What is the coefficient in this regression formula: Length = 3.5 + 1.29 mass

1.29

In a Variable Gage R&R, the acceptable % contribution of variation attributable to Repeatability and Reproducibility should be less than _____%

10

When the variance inflation factor of an independent variable is larger than ______ there is large multicollinearity for this variable in the model?

10

Which of the following is not an example of continuous data?

15 out of 47 people left the bus

the first test in the Western Electric Rules is to check whether any one point on the control chart is more than ______ standard deviations away from the center line?

3

For the normal distribution, about _____% of the data fall within +/- 2 standard deviation from the mean?

95

What is the recommended subgroup size when using Xbar-S chart to check for process stability?

>10

Which of the following is TRUE about Type I and Type II errors?

A Type I error is incorrectly rejecting the Null Hypothesis (HO) while Type II error is failing to reject the Null Hypothesis (HO) when you should

Which of the following represents the information we are trying to achieve by seeking input from our customers in determining what is important to them?

CTQ's

A two-sample T-test does which of the following?

Compares the means to determine if sample 1 is statistically difference from sample 2

As a standard for a process to be at the 6 Sigma quality level, it must have?

Cp & Cpk > 2

Select all reasons why one financial benefit estimation might differ from another?

Different assumptions on project duration Use of different discount rates different assumption on project costs

Whis is not indicative of statistical inference

Estimating population parameters using the inverted w sampling method

Which of the following situations does NOT indicate that the simple linear regression model is statistically significant?

F-statistic of ANOVA is smaller than the critical statistic

One-tailed hypothesis test is used when we care about whether there is a difference between groups and we don't care about the direction of the difference ?

FALSE

Early in a LSS project a Belt may assemble a number of people familiar with the process to identify various ways something could fail and what problems that failure would cause. Which tool would the belt use for this?

FMEA

If a hypothesis test shows a p-value of 0.28, but we see a practical difference, what could be reasons for failing to reject the null when there may be a difference?

Sample size too small Human error in data collection

A Black Belt stores tolls in marked locations so that workers can find & access them easily when they re needed. which principle of 5S methodology is the black belt applying?

Straightening (set in order)

Which statement describes an undesirable situation when implementing SPC?

The MR chart of an IMR chart is out of control but individuals chart is in control

How is variance calculated?

The average squared distance of each data point from the mean

What is Bias?

The difference between the observed value and the true value

In which conditions can the null hypothesis be rejected?

The test statistic is greater than the critical value P-value is smaller than alpha level

Which is incorrect about U-charts?

U-chart control limits will always be straight lines

To achieve Six Sigma the DMAIC methodology follows which approach

Use the transfer function Y=f(x)

Mistake proofing is defined as...

Using wisdom or ingenuity to create devices allowing 100% defect free steps 100% of the time

To understand the CTQ attributes of a product or service, we need to get?

VOC

For a good control chart implementation, you should re-calculate control limits and center-lines often?

false

If Kappa is equal to 0, the measurement system is excellent?

false

Which test should be used to compare the average results of 7 different Green Belt classes?

anova

What are confidence intervals (CI)?

at certain confidence intervals with upper confidence limits (UCL) and a lower confidence limit (LCL) has a x% chance of containing the true mean

you can use an individuals chart to track process outputs and to detect the presence of special causes using a sample size of 1?

correct

Who is credited as being the father of Six Sigma?

bill smith

The underlying distribution of the P chart is the _____ distribution?

binomial

Which distribution has mean equal to np and the variance equal to np(1-p)?

binomial distribution

Who should have the most influence when writing a business case for a project?

business owner, process owner

Which is not a characteristic of a successful team?

complacency exists

What type of data do we prefer?

continuous

The Xbar chart plots the average values of each of a number of small sampled subgroups

correct

_______ are flaws, errors or other non-conformities that compromise the value of a product

defects

_________is applied to describe the main characteristics of a collection of data?

descriptive statistics

when it comes to control, one of the most effective means of eliminating defects is to

design defect prevention into the product or process

An estimate of the probability of an event occurring depending on the standard deviation from the Mean is based on?

empirical rule

A Control Plan is finalized at the end of a LEAN Six Sigma project and given to the Process Owner so she/he can follow it exactly for the remaining life of the process

false

A correlation coefficient of 0.00 means there is absolutely no relationship?

false

A reduction in any type of Muda will always reduce outliers and defects?

false

Achieving Six Sigma has nothing to do with meeting customer expectations?

false

Cause & Effect Diagram provides quantitative analysis of correlation between each cause and the effect.

false

Control charts are valid only if the data are normally distributed?

false

Correlation implies causation?

false

Cp, and Pp take both the variation and the average of the process into consideration when measuring the process capability?

false

A ________ is a graphical tool to present the distribution of the data

histogram

A _________ test is a statistical method in which a specific hypothesis is formulated about the population, and the decision of whether to reject the hypothesis is made based on sample data ?

hypothesis

5S Sorting: Items used weekly should be kept _______?

in a local location

Kanban systems are quick fixes to large inventory problems, workforce issues, poor product planning, fluctuating demand cycles etc.

incorrect

Which of the following are ways in which you might deal with multicollinearity?

increase the sample size Remove the variable with high mulitcollinearity and high p-value

A method utilized to streamline workflow in a manner that minimizes waste through the use of signals that trigger "flow" through each process step is known as?

kanban

When the p-value is _____ than the α level, we reject the null and claim that there is a statistically significant difference between different groups ?

less

which is an example of hard savings?

lowered inventory carry8ing costs factory costs reduction cycle time improvements lowering overtime hours paid

What do we need to know to completely describe a normal distribution?

mean and variance or standard deviation

If extreme outliers exist in a dataset, this would warrant the use of __________ to illustrate the center location.

median

Mann-Whitney test is a statistical hypothesis test to compare the _______of two populations which are not normally distributed?

medians

Which of the following best describe Six Sigma?

metric, methodology, management system

How might you display central location on a nominal scale?

mode

Regression analysis does not rely on this assumption about the residuals

non constant variance

Which of the following tests would you use to determine if there is a statistically significant difference between a population mean and a specified value?

one sample t test

what is a y measure

output

_________ is when more products are produced than are required by the next function or customer.

over production

If we produce more than is needed by the next step in the process or more than the customer needs this is an example of which element of waste?

overproduction

In most cases, an project team is most autonomous and receives the least amount of direction during which of the following stages?

performing

Select all that are desired outcomes of a Six Sigma program or project

permanently eliminate the root cause of defects maximize the bottom line for the business customer satisfaction

If a set of data is very similar in value from point to point yet far off the mark relative to a given target value, this data could be said to be...

precise but not accurate

__________ is how consistent measurements deliver the same values under the same circumstances?

precision

What are some key outputs of the Define phase?

primary metric with baseline project charter

Which of the following indicates a strong inverse relationship?

r= -0.85

Which is not an example of hard savings?

regaining lost sales

What does a variance inflation factor (VIF) greater than 10 indicate?

regression coefficients are confounded and are unacceptable

Variation in measurements made by different appraisers using the same measuring instrument when measuring identical objects is referred to as?

reproducibility

_______ are the vertical differences between actual values and the predicted values or the "fitted line" created by a regression model?

residuals

Select only those that are examples of graphical analysis tools

scatter plots histograms box plots run charts

The risk prioritization number is the product of the ______ score, _____ score and ______ score?

severity, occurence, detection

Select any of the following that are collective elements of a great control plan?

standard Operating Procedures Response Plans Training Plans Communication Plans Audit Checklists

Population is grouped into distinct and independent categories and then samples are randomly or systematically selected in each category of the population. Which sampling strategy is it?

stratified sampling

Which principle of the 5S methodology is about avoiding falling back to the old ways of cluttered and unorganized work environment?

sustaining

When a Belt adds information to a Process Map that defines which department is responsible for the various activities displayed, it could be referred to as _____________?

swim lanes

Regression analysis does not rely on this assumption about the residuals (differences between predicted and actual Y values)

the poisson distribution

Which of the following assumptions is NOT required to ensure the reliability of the linear regression model?

the underlying population relationship is non linear

In the following hypothetical regression equation, Flavor is more heavily influenced by which factor? Flavor = (124 + 0.98*temp - 9*time)

time

What is the primary purpose of linear correlation analysis?

to measure the strength of the linear association between two variables

When are correlation and linear regression not used?

to understand what happens to the value of X when the value of Y is increasing by one unit

A Cause & Effect Diagram is used to identify, organize and graphically display the potential causes of a specific effect or event?

true

A t-test is a hypothesis test in which the test statistic follows a student's t distribution if the null hypothesis is true ?

true

CTQ's are translated from VOC

true

Capability Analysis is a measurement of the ability of the process to meet specified requirements.

true

Communication plans are intended to plan and prepare for the dissemination of information?

true

Continuous variables are measured, Discrete variables are counted?

true

Cp considers the within-subgroup standard deviation and Pp considers the total standard deviation from the sample data?

true

Hypothesis testing can help establish a statistical difference among factors in data sets?

true

If VIF = 1, there is no multicollinearity?

true

If a process is stable, the future performance of that process is predictable within certain limits?

true

In Six Sigma Primary and Secondary Metrics are Mandatory

true

Lean and Six Sigma are Both focused on Quality & Value for the customer?

true

Multicollinearity is the situation when two or more independent variables in a multiple regression model are correlated with each other?

true

Net Present Value (NPV) is total value of all future cash flows discounted to today's value?

true

One of the primary objectives of constructing an X-Y Matrix is to separate the vital few X's from the trivial many.

true

One sample t-test is a hypothesis test to study whether there is a statistically significant difference between a population mean and a specified value or target ?

true

One-way ANOVA (one-way analysis of variance) is a statistical method to compare means of two or more populations?

true

Poka-Yoke eliminates the defect as early as possible in the process

true

R2 is also referred to as the coefficient of determination?

true

R2 measures the proportion of variability in the data which can be explained by the model?

true

Return on Investment (ROI) is the ratio of net financial benefits (either gain or loss) on a project or investment, to the financial costs?

true

Standard Deviation is a measure that describes how far the data points spread away from the mean?

true

The data on SPC charts are typically constructed such that the most recent data point is the last one on the right?

true

The higher a Sigma level the better?

true

The higher the confidence level, the wider the confidence interval ?

true

The more variability, the wider the confidence interval?

true

The null hypothesis for a Paired t-test is: MuA - MuB = 0

true

The null hypothesis for a normality test is that the data are normally distributed?

true

The process of selecting a subset of observations within a population is referred to as sampling ?

true

The proportion of the area under the sampling distribution and beyond the test statistic is p-value?

true

The use of Kanbans work best with pull systems for determining the timing of which products or services are produced

true

Variation of the outputs of a process refers to how broadly distributed the results are relative to the average.

true

in an EWMA chart, the more recent data gets more weight than the older data?

true

isx Sigma originated in the 1980's at Motorola?

true

the japanese word for waste is muda?

true

the subgroup size of an Np chart are constant?

true

α risk is the risk of making a Type I error ?

true

From the following, select those that are characteristics of a Lean Enterprise

value add flow pull systems availability flexibility zero waste

The use of station warning lights, tools boards, and jidohka devices represents the use of which lean concept?

visual factory

the lean technique that focuses on making "important work flow issues" noticeable is called?

visual factory

Much of the efforts in a LEAN Six Sigma project are driven by a concept called VOC which stands for:

voice of the customer

Control charts and their limits are the?

voice of the process

how should CTQ's not be established

what you think the customer wants

What statistic is used for sampling?

xbar

Which pair of control charts is most preferred for subgroup sizes of 10 or less using continuous data?

xbar-R charts

"Is the following problem statement well constructed?During 2012 the average cycle time for a Michigan factory product named "B352" was 237 seconds vs. a target of 218 seconds representing a gap of 19 seconds over target, costing the company $9356 per month or $112k per year. The goal of this project is to reduce "B352" cycle time to 218 seconds by the end of Q3 2013.

yes

What are Discrete Data?

yes/no/sometimes