Term

Definition
Six Sigma is about applying a structured, scientific method to improve any aspect of a business, organizaiton, or process. It's about engaging in disciplined data collection and analysis to determine the best possible ways of meeting your customer's needs while satisfying yours. Primarily, it's a program designed to reduce process variation. 


Term
What is Six Sigma's role in the organization? 

Definition
Six Sigma's role is to help management produce the maximum value, while using minimum resources. It applies scientific principles to processes and products. By using the DMAIC (Define, Measure, Analyze, Improve, Control) approach processes or products are improved in the sense that they are more effective, more efficient, or both. 


Term
How is Design for Six Sigma (DFSS) used? 

Definition
If no process or product exists, or if existing processes or products are deemed beyond repair, then design for Six Sigma (DFSS) methods are used to create effective and efficient processes or products. Designing for Six Sigma includes eliminating sources of error. 


Term
What is involved in the Define phase of the DMAIC process? 

Definition
Project charter VOC tools (surveys, focus groups, letters, comment cards) Process map QFD, SIPOC Benchmarking 


Term
What is involved in the Measure phase of the DMAIC process? 

Definition
Measurement system analysis Exploratory data analysis Descriptive statistics Data mining Run charts Pareto analysis 


Term
What is involved in the Analyze phase of the DMAIC process? 

Definition
Identify the root causes of defects, defectives or significant measurement deviations whether in or out of specifications (the "X"s, independent variables)......Causeandeffect diagrams.... Tree diagrams.... Brainstorming.... Process behavior charts (SPC).... Process maps.... Design of Experiments.... Enumerative statistics (hypothesis testing).... Inferential statistics (Xs and Ys).... FMEA.... Simulation 


Term
What is involved in the Improve phase of the DMAIC process? 

Definition
Reduce variablility or eliminate cause......Force field diagrams.... 7M tools.... Project planning and management tools.... Prototype and pilot studies, 


Term
What is involved in the Contol phase of the DMAIC process? 

Definition
With the desired improvements in place, monitor the process to sustain the improvments......SPC.... FMEA.... ISO 900x.... Change budgets.... bid models.... cost estimating models.... Reporting system 


Term

Definition
Six Sigma is a highly disciplined process that focuses on developing and delivering nearperfect products and services consistently. Six Sigma is also a management strategy to use statistical tools and project work to achieve breakthrough profitability and quantum gains in quality. 


Term
In a normally distributed process, what percentage of measuremens will fall within +/ 3 sigma of the process mean? within +/4.5 sigma? 

Definition
99.73% of the measurements will fall within +/ 3 sigma and 99.99966% will fall within +/ 4.5 sigma. 


Term
Where does +/ 6 sigma come from and how many defects per million opportunities is it associated with? 

Definition
Motorola noted that many process operations tended to shift 1.5 sigma over time. A normally distributed process with normally distribution variation about the mean, would need to have specification limits of +/ 6 sigma in order to produce less than 3.4 defects per million opportunities. 


Term
What % of measurements from a normally distributed process are included within +/ 3 sigma boundaries? within +/ 4.5 sigma? 

Definition
99.73% within +/3 sigma and 99.99966% within +/4.5 sigma. 


Term
Wat are the defect levels (PPM) associated with +/1,2,3,4,5,6 sigma level boundaries? 

Definition


Term
What business successes result from a Six Sigma initiative? 

Definition
Cost reductions....Market share growth....Defect reductions....Cultural changes....Productivity improvements....Customer relations improvements....Product and service improvements....Cycletime reductions 


Term
Why does Six Sigma work (according to Snee 1999)? 

Definition
Bottom line results....Senior management buy in....DMAIC provides disciplined approach....Short project completition times (3 to 6 months)....Clearly defined measures of success....Infrastructure of trained individuals (black belts)....Customers and processes are the focus....With backbone of sound statistical approach 


Term
What does SIPOC stand for? 

Definition
Suppliers, Inputs, Process, Outputs, and Customers 


Term
Draw an Expanded SIPOC Model. 

Definition


Term
What is the advantage of using a SIPOC model? 

Definition
Display a cross functional set of activities in a single, simple diagram.... create a big picture perspective to which additional detail can be added....Use the same framework for either large organizations or smaller processes (Pande 2000).......The ultimate goal is to identify essential work flows and sources of variation in work over time......SIPOC captures the key components of sucess from suppliers, through internal processes and on to key customers. 


Term
How do Black Belts typically function in an organization? 

Definition
In some organizations, BBs are full time positions that report directly to management sponsors, who, in turn, have specific projects for them. In other organizations, BBs continue in their normal assignments and participate in process improvement teams as needed. In this structure, BBs act as internal consultants and are pulled into teams when their specific skills are needed. 


Term
What are some of the considerations for developing a Six Sigma project? (Harry 2000) 

Definition
Fopcus on project cost savings....Focus on customer satisfaction deliverables....Focus on processes....Focus on problems....Focus on a targeted locations....Focus on design....Focus on supplier processes 


Term
What is the key to achieving Six Sigma improvements? 

Definition
The characterization, measurement, analysis, and control of variation is the central theme of Six Sigma. 


Term
What is common cause variation? 

Definition
Some variation is just natural; you can't eliminate it. This type of variaiton is called common cause variation. You can act to reduce common cause variaition, but you can't eliminate it. In coin tosses, the variaition in the number of heads from set to set is perfectly normal. 


Term
What is special cause variation? 

Definition
Special cause variation is directly caused by something special. With Six Sigma your effort is spent in identifying the difference between common cause variation and special cause variation. 


Term
Which type of variation (special or common cause) should a Six Sigma project concentrate on first? 

Definition
In general, it's best to work on reducing specialcause varation before trying to reduce commoncause variation. The reason is because when you have specialcause variation, the process is not stable or predictable, and you can't be sure of what's happening. 


Term
Assume a 1 on a die represents a defect. What is the probability of rolling 100 dice without a defect (i.e., without a 1)? 

Definition
(5/6)^100 = 0.000000012 probability or about 1 chance in 82,817,975 


Term
How does Vilfredo Pareto's 80/20 rule apply to Six Sigma? 

Definition
20 percent of a system's inputs accounts for 80 percent of the influence on that system. While a great number of factors are connected to a given outcome, only a few carry the weight to change that outcome in a significant way. In a process, a few key variables are the cause of most performance problems or defects. 


Term
What's at the heart of the Six Sigma process? 

Definition
Datadriven decision is an integral part of a Six Sigma program. 


Term
What do each of the DMAIC components contribute? 

Definition
Define the problem......Measure the extent of the problem.....Analyze the sources of variation......Improve the process.....Control the process for sustained improvement. 


Term
What is the acronym meaning of SWOT? 

Definition
Strengths
Weaknesses
Opportunities
Threats 


Term
In SWOT analysis, what does the S stand for and mean? 

Definition
S stands for strength. It's something the company is good at doing. Examples: Engineering expertise, Technical patents, Skilled workforce, Solid financial position, Reputation for quality 


Term
In SWOT analysis, what does the W stand for and mean? 

Definition
W stands for weaknesses. A weakness is something the firm lacks or is a condition that puts it at a disadvantage.
Examples: Poor cash flow, Outdated technology, High overhead expenses, Lack of access to skilled labor, Poor quality perception by customers 


Term
Quality History Influencing Six Sigma
Philip B. Crosby (1928  2001) 

Definition
While other quality deep thinkers could be viewed as aqcademicians, Crosby was considered a businessman. Crosby stated that corporate management must make the cost of quality a part of the financial system of the company.
Four absolutes of quality
Quality is conformance to requirements, and requirements are what the customer says they are.
Quality comes from prevention
The quality performance standard is zero defects.
Quality measurement is the proce of nonconformance.
Crosby also developed a 14step approach to quality improvement. 


Term
Quality History Influencing Six Sigma
Dr. W. Edwards Deming (1900  1993) 

Definition
Developed the 14 Obligations of top management and the 7 deadly diseases that management must cure.
Some of the 14
Cease dependence upon inspection as a way to achieve quality.
End practice of awarding business based on price tag
Eliminate slogans/targets asking for increased productivity without providing methods 


Term
What was Deming's chain reaction with Japan in the summer of 1950? 

Definition
Improve quality > Decrease cost (less rework, fewer delays)>Productivity improves > Capture market with better quality and price > Stay in business > Provide jobs 


Term
Quality History Influencing Six Sigma
Dr. Armand V. Feigenbaum (1920  ) 

Definition
Feigenbaum is given credit for establishing the concept of total quality control. TQC maintains that all areas of the company must be involved in the quality effort. 


Term
An organized and disciplined approach to problem solving in most Six Sigma organizations is called:
a  SIPOC
b  DMAIC
c  PDCA
d  DPMO 

Definition
b  DMAIC (Define, Measure, Analyze, Improve, Control) 


Term
Using Six Sigma methodology, a company at 4.5 sigma would have a failure rate of
a  3.4 ppm
b  233 ppm
c  1350 ppm
d  6210 ppm 

Definition


Term
Just as the jury in a criminal trial, we are not infallible in our judgments. In spite of our best efforts, errors happen. What are these errors? There are two types: In a criminal court situation, we could convict an innocent man or acquit a criminal. 

Definition


Term
Describe Type I and Type II errors. 

Definition
cause of the punishment involved, the first is considered by far the more serious of the two. There are also penalties in hypothesis testing. Hence, rejecting the null hypothesis when it is true is called 'Type I error' (the more serious error) and failing to reject the null hypothesis when the alternative is true is called 'Type II error' (the less serious error). 


Term
Describe Type I Error (alpha risk). 

Definition
Type I Error (α) In Hypothesis Testing, as in most judicial systems, Type I Error (convicting an innocent person) is considered the more serious of the two potential errors. The probability of this error is denoted by α (alpha) and is also known as the Significance Level of a test. Thus, alpha represents the amount of "risk" we're prepared to take in erroneously rejecting the null hypothesis. 


Term
Describe Type II Error (Beta risk). 

Definition
Type II Error (β) Type II error (not convicting a guilty person) is the "lesser" of the two errors and its probability is denoted by β (beta). Ideally, we would want to eliminate or at least minimize both forms of error to increase the chance of making the right decision (correct verdict). Unfortunately, it is not possible to minimize the two errors simultaneously since reducing one leads to an increase in the probability of the other. We try to overcome this problem by setting alpha (the more serious error) at a maximum acceptable level (the convention being 0.05, or 5%) and minimizing beta (the convention being 0.20, or 20%). 


Term
Sketch an example of a Type I error. 

Definition


Term
Sketch an Example of Type II error. 

Definition


Term
What is the power of a test? 

Definition
The Power of a test answers the question: If the null hypothesis is false, what is the probability that the data from the experiment will reject the null hypothesis? In other words, Power is the chance of finding a significant effect when one does exist. Naturally, a highpowered test is desirable. As you will see below, however, several factors are tied to the power of the test, and the goal of a Power Analysis is to strike a balance among these factors so as to achieve the most sensitive test given the available resources. 


Term
What are four factors that impact a test's power (or beta risk)? 

Definition
Size of Effect
Significance level (apha risk)
Sample size
Population standard deviation 


Term
How does the effect size impact the Power or beta risk? 

Definition
The larger the size of the effect you're looking for, the better your chance of finding it. 


Term
How does the alpha risk level impact power? 

Definition
If avoiding a Type I error were the only concern, you would always fix alpha at a low level such as 0.01 or 0.05. But things are not so simple, because Type I and Type II errors are interdependent: as one decreases, the other increases. Since power is computed as (1β), this means that power and alpha are directly related: for a given effect and sample size, as alpha increases, so does the power. Therefore, select alpha based on the study goals. For instance, if it is important not to overlook a potential effect, such as for a promising new drug compound, use a higher alpha, say 0.2. If on the other hand, the new drug carries the risk of serious sideeffects, you might want to be stricter and use a low alpha level, say 0.01. 


Term
How does sample size affect the power or beta risk? 

Definition
Sample Size (n): The study sample must be sized appropriately in order to meet its goals. If the sample is too small, the test is likely to be inconclusive, even if an effect of practical importance does exist. On the other hand, an oversized study uses more resources than necessary and may detect an effect that is statistically significant, but of little practical importance. For a given effect size and significance level, the larger the sample size, the greater the power of the associated test. 


Term
How does the population standard deviation affect power? 

Definition
Population Standard Deviation (σ): Variability in the process can obscure the signal, rendering the test less powerful. It is closely related to sample size  the more variable the data, the larger the sample size needed to detect an effect of a given magnitude. With the exception of the test for proportions, some measure of variability is required as an input to all power and sample size calculations. In general, the larger the population standard deviation, the lower the power. The problem is that we don't usually know the variance of the population! This problem can be resolved by using data from a pilot study to estimate the variance. It is also useful to keep in mind that paired and repeated measures designs have lower overall variability than those with independent samples. 


Term
Sketch the impact that varying a test's alpha risk has on its power. 

Definition


Term
Which of the following options is true? Power increases as:
A  Sample size decreases
B  Variance increases
C  Effect size decreases
D  Significance level increases 

Definition
D  Power increases as Effect size increases, variance decreases, sample size increases and significance (alpha) level increases. 


Term
A regional manager of a pharmacy wants to test whether there is a difference between the oder fill rates at the company's two locations. A previous study at location 1 found a fill rate of 90% (p1=0.9). What is the sample size required to detect an orde 

Definition


Term
What is the basic philosphy behind Six Sigma? 

Definition
The idea that removing variability from upstream operations that are inputs to a process will yield defectfree outputs. Inputs are often referred to as "Xs" and outputs are referred to as "Ys". The output that we're concerned about is called Critical to Quality Characteristic (CTQC). 


Term
What are the central activities of a Six Sigma project? 

Definition
The only way to eliminate variation downstream is to find the sources upstream and reduce them. Identifying and resolving these upstream root causes of variation (or defects) are the central activities of a Lean Six Sigma project. 


Term
Sketch the process map for a Six Sigma process aimed at reducing call holding time. 

Definition


Term
Where is much of the initial effort of a six sigmal process directed? 

Definition
Much of the initial effort of a Six Sigma project is to identify the X's (inputs), determine which inputs (X's) are significant, and quantify the relationship between those X's and Y (output). 


Term
Relate the Y = f(X) expression to our holdtime reduction project. 

Definition


Term
Diagram a simplified relationship between the inputs of a process and the process outputs. Variability (defects) in the end product or service is a function of input variability, which is in turn a function of one or more root causes. 

Definition


Term
What is the goal of Six Sigma? 

Definition
The goal of Six Sigma is to identify the significant inputs, then tackle the root causes of their adverse variability through improved process controls, errorproofing, redesign for manufacturabiltiy, and other methods. 


Term
Consider the new guest checkin process at a hotel. If Y=f(x), and Y is the time required to check in, what are some of the hotel factors you might consider Xs? 

Definition


Term
What is Six Sigma according to Pande, Neuman, and Cavanagh in their book " The Six Sigma Way"? 

Definition
A comprehensive and flexible system for achieving, sustaining and maximizing business success. Six Sigma is uniquely driven by close understanding of customer needs, disciplined use of facts, data and statistical analysis, and diligent attention to managing, improving, and reinventing business processes. 


Term
List some of the benefits of Six Sigma process management. 

Definition
Effective management of process improvement projects
Consistency of performance
Reduces fire fighting
Finds rootcause solutions to problems
gives an improved customer focus
leads to better informed management and better informed meetings 


Term
Which part of the DMAIC process would "define current and desired future process states" fall? 

Definition


Term
Which part of the DMAIC process would "reduced cycle time" fall? 

Definition


Term
Which part of the DMAIC process would "prevent defects" fall? 

Definition


Term
Which part of the DMAIC process would "reduce defects and improve material flow" fall? 

Definition


Term
Which part of the DMAIC process would "document processes" fall? 

Definition


Term
Which part of the DMAIC process would "process reliability" fall? 

Definition


Term
A mortgage company identified 35 possible defects that could occur during a loan application. Their records show that 2,500 loans were processed last year, and out of those loans, 3,500 defects were identified. So what is the sigma level? 

Definition
Each of the 2,500 loan applications represented 35 defect opportunities, for a total of 87,500 opportunities. Actual experience was 3,500 defects.
Defects per million opportunities is therefore: (3,500/87,500) x 1,000,000 = 40,000
At a level of 40,000 Defects Per Million Opportunities, the company is operating at a Sigma Level between 3.0 and 3.5. 


Term
A bank determined that loan approval process has 25 defect opportunities. During the recent quarter, the bank processed 373,560 mortgage applications. On those, 57,400 errors were corrected. What is the DPMO and Sigma Level for the process? 

Definition
DPMO = (# Defects x 1,000,000) / ((# Defect Opportunities/Unit) x # Units)
DPMO = (57,400 x 1,000,000) / (25 x 373,560) = 6,146
From the Six Sigma Conversion Table, you can see that a DPMO level of 6,146 corresponds to a Sigma Level of 4.0. 


Term
Co builds deck furniture. 7 different defects can arise in chair mfg. Over six months it built 1,746,932 chairs. During that period, 14,566 defects were noted. What is Company's defects per million opportunities (DPMO) level and sigma level? 

Definition


Term
What are some of the more familiar tools that are employed within the Six Sigma structure? 

Definition
Process Mapping
Statistical Process Control
Design of Experiments
ErrorProofing
Measurement System Analysis
Failure Mode and Effects Analysis 


Term
What is the acronym DFSS mean? 

Definition
Six Sigma also includes Design for Six Sigma (DFSS) methodologies and tools for developing new products, services and processes. DFSS provides a pathway to marketable innovation. Like DMAIC, practicing DFSS means focusing on customer requirements and instituting practices to assure requirements are met at near perfection. 


Term
In which phase of the Six Sigma improvement process are performance standards defined?
Define
Measure
Analyze
Improve
Control 

Definition


Term
In which phase of the Six Sigma improvement process are potential solutions identified and evaluated?
Define
Measure
Analyze
Improve
Control 

Definition


Term
More than anything the DMAIC process is what? 

Definition
More than anything, the DMAIC process is a systematic critical thinking exercise  a process of asking and answering questions. 


Term
What is definition of defect?
A  variable product/process (PP)
B  PP doesn't perform as well as competition
C  PP doesn't meet customer requirements for use
D  PP that is unreliable
E  PP requiring extra processing 

Definition
C  A product/process that does not meet customer requirments for use. 


Term
What is primary Six Sigma approach to reducing defect level?
AAdd inspection
Breduce process variability
CRevice specifications to better reflect customer expectations
DAdd workforce incentives
EManage Customer Expectations 

Definition
BReduce process variability at the source through redesign or process controls. 


Term
What is the strongest guiding force of Six Sigma decision making?
AProcess owner experience
BHistorical best practices
COpinions of Senior Management
DData and statistical analysis
EBenchmarking studies of competition 

Definition
D  Data and statistical analysis are the strongest guiding force for Six Sigma decision making. 


Term
Company provides two services. Process A can be defective 15 different ways. Process B only 5 ways. Company produces 500 As and 1000 Bs. A total of 27 defects experiences. What is DPMO for overall process? 

Definition
DPMO (Defects Per Million Opportunities)
DPMO = (27 x 1000000)
divided by (15 x 500)+(5 x 1000)
DPMO = 2160 


Term
A company generates 22,700 defects per million opportunities. What is the Sigma level performance of the company?
A4.0
B3.7
C1.2
D2.8
E3.5 

Definition
22,700 defects = 3.5 sigma level performance and a Cpk of 1.167 (sigma level/3). 


Term
At what step in the Six Sigma improvement process are efforts made to identify the root cause of process variability?
ADefine
BMeasure
CAnalyze
DImprove
EControl 

Definition


Term
At what step in the Six Sigma improvement process is a Process map of the process created?
br>ADefine
BMeasure
CAnalyze
DImprove
EControl 

Definition


Term
Which of the following is NOT part of a value stream?
AProcess inputs from suppliers
BThe channel of distribution
CCost comparison by consumers
DProcesses that transform materials or information
ENew order processing 

Definition
CCost comparisons by consumers 


Term
Which is NOT a reason to map the value stream?
ATo document who is responsible for specific actions.
BIdentify process inputs
CIdentify waste sources
DCommunicate the process graphicaly
EIdentify internal/external customers 

Definition
ATo doumnent who is responsible for specific corrective actions.
The purpose of a value stream is to map the process to show the inputs, outputs, suppliers and customers involved in the process. Its objective is not to document who is responsible for specific corrective actions. 


Term
Sorting through error data from a shipping process, a team wants to develop action priorities. What tool should the team analyze the data with?
AProcess Mapping BBrainstroming CPareto Chart DCorrective Action Matrix ETrend Chart 

Definition


Term
"Process Improvement" refers to a strategy of finding solutions to eliminate the root causes of performance problems in a process that already exists in your company. What is the Six Sigma approach? 

Definition
Process improvement efforts seek to fix problems by eliminating the causes of variation in the process while leaving the basic process intact. In Six Sigma terms, Process Improvment teams find the critical Xs (causes) that create the unwanted Ys (defects) produced by the process.
Define the problem and what customers require
Measure the defects and process operation
Anaylze the data and discover causes of the problem
Improve the process to remove causes of defects
Control the process to make sure defects don't recur. 


Term
Break down the DMAIC components for a Process Improvement problem. 

Definition
Define: identify the problem
define improvment requirements
set direction goals
Measure: validate problem/process
refine direction goals
measure key steps/inputs (Xs)
Analyze: develop causal hypothesis
identify 'vital few' root causes
validate hypothesis
Improve: develop ideas to remove root causes
test solutions
measure results
Control: establish standard measures to maintain performance
correct problems as needed 


Term
What does the acronym CTQ mean and why is it important to the Six Sigma process? 

Definition
CTQ  Critical to Quality
The first step in calculating sigma or in understanding its significance is to grasp what your customers experct. In the language of Six Sigma, customer requirements and expectations are called CTQs. 


Term
Calculating sigma for Pizza business. Four quality requirements are: correct ingredients, hot, on time, and undamaged (4 defect opportunities for each pizza). 500 pizzas delivered had 25 late, 10 too cold, 7 damaged, 16 wrong ingredients. What's sigma? 

Definition
To calculate sigma, take the total number of defects counted, divide by the total number of units tested multiplied by the number of defects possible per unit.
(25+10+7+16)/(500X4) = 0.029 defects per opportunity (DPO) or 29,000 defects per million opportunities (DPMO) which equals 3.4 sigma (97.8% yield). 


Term
What is the primary approach employed by Six Sigma to reduce the number of defects? 

Definition
Reduce process variability at the source through redesign or process control 


Term
What is the primary purpose of Six Sigma? 

Definition
Improve profitability and/or other key performance metrics 


Term
What is the strongest guiding force of Six Sigma decision making? 

Definition
Data and statistical analysis 


Term
At what step in the Six Sigma improvement process are efforts made to identify the root cause of process variability? 

Definition


Term
At what step in the Six Sigma improvement process is a Process Map of the process created? 

Definition


Term
Processes that include steps where value is created as defined by the customer are called what? 

Definition
Value Stream or Supply Chain. Six Sigma strives to eliminate activities that don't produce value 


Term
What is the purpose of a value stream map of the process? 

Definition
To show inputs, outputs, suppliers and customers involved in the process. Its objective is not to document who is responsible for specific corrective actions. 


Term
A team is sorting through error data from a shipping process and wants to develop priorities for action. What tool should the team use to analyze the data? Process Mapping, Brainstorming, Pareto Chart Corrective Action Matrix, Trend Chart 

Definition


Term
Team's working on a project to accelerate accounts receivable collections. They want to eliminate redundant or wasteful process steps so overall cyle time can be improved. What type of process map would be best choice? SIPOC Map, Flow Chart, Value Added 

Definition


Term
Why are control limits set at +/3 sigma? A3 std devs gives adequate room for process to vary over time
BThey represent the best balance between control and chaos
They provide the best economic balance between false signals and no signal. 

Definition
CThey provide the best economic balance between false signals and no signals. 


Term
What is the basis of the theory of statistical process control?
Control Theory Law of Averages Laws of Probability Correlation Analysis Law of Unintended Consequences 

Definition


Term
A Six Sigma team at an insurance company has been working on a project to reduce the number of claim defects leading to denied claims. A control chart of claim denials is outofcontrol. What conclusion should the team draw from this condition? 

Definition
The process is unstable over time. 


Term
A Six Sigma team is working to reduce the frequency of medical errors, and wishes to track the number of errors per patient per day. Which type of attribute control chart should the team use? c Chart, p Chart, np Chart u Chart or cp Chart? 

Definition
The u chart would be correct because it measures defects per unit (errors per patient) and accomodates a varying sample size. If a constant sample size were used, the X and Moving Range chart would be appropriate. 


Term
A diagnostic lab chartered a Six Sigma team to reduce the sample frequency with label problems. The team wishes to chart the % of samples with a label problem. Volume is high and stable enough to assume a constant sample size. Which attribute chart? 

Definition


Term
Six Sigma team is works to reduce bad debts by tracking $ receivables over past 90 days. Using Individuals and Moving Range chart, avg balance outstanding is $736,50, and Median Moving Range is $58,000. What is upper control limit for Individuals chart? 

Definition
$918,620
The Upper Control Limit of an XmR chart using the median moving range is: Xbar plus 3.15 times the median moving range, or $736,500 + 3.14x$58,000. 


Term
A Six Sigma team within the Finance Dept works on a project to reduce the # journal entry errors, which delay monthly closing process. Team wishes to track the % of erroneous entries using a p chart. If pbar is 0.036 and n=2,000, what is the UCL? 

Definition
0.048
The Upper Control Limit is: pbar plus 3 times the square root of ((pbar times (1 minus pbar))divided by n) or 0.036 plus 3 times the square root of ((0.036 times (1 minus 0.036))divided by 2000). 


Term
An order processing operation has a specification of 4.0 hours +/ 1.0 hours. The process mean is 4.2 hours, with a std dev of 0,25 hrs. The process is stable and normally distributed. What is Cp and Cpk for the process? 

Definition
Cp=(USLLSL)/(6x sigma(short term))
Cp=(53)/(6x 0.25) = 1.33
Cpk=minimum (USLXbar or XbarLSL)/(3x sigma(short term))
Cpk = 1.07 


Term
A Six Sigma team wishes to calculate Cpk in order to assess the capability of an order entry process. The team has determined that the process data are not normally distributed (distribution is skewed). What should the team do? 

Definition
Transform the data to more closely fit a normal distribution. 


Term
There are three primary categories of investigation in the Analyze phase of the DMAIC cycle. What are they? 

Definition
Characterize the current process (What is the current state of affairs?)  Analyze I
Compare Treatments (Which treatment, or action, is more effective?)  Analyze II
Model the Process (Understand Relationships, How does X impact Y?)  Analyze III 


Term
In the Analyze phase of the DMAIC cycle, one seeks to uncover various root causes impacting the process. How does the root cause determination work? 

Definition
The path to determine a root cause is not a straight line. We start with general experience and through deduction try to draw specific conclusions, theories, or hypotheses. Those hypotheses are then tested for "truth", and the results in turn alter our general understanding (induction). The loop continues to cucle through this process of deduction and induction until the hypothesis is confirmed. 


Term
A Six Sigma team at Acme Building is working on a project to reduce the frequency of shipping errors. The team is unsure of the root causes for the problem. What type of chart should be contructed to uncover root causes? 

Definition


Term
What questions are Fishbone Diagrams used to answer? 

Definition
What are the potentional root causes of a proble?
What category of process inputs represents the greatest source of variability? 


Term
Which is a primary use of Fishbone Cause and Effect Charts?
AProvide a project road map
BQuantify relationship between input and output
CShow process performance over time
DCategorize process inputs by department
EIdentify po 

Definition
EIdentify potential root causes of variability 


Term
A Six Sigma team wants to learn more about the causes of defects in an insurance claim submission process. Which two tools would be most appropriate?
Trend Chart & Pareto Chart
5Why Analysis & Histogram
Fishbone Diagram & 5Why Analysis 

Definition
Fishbone Diagram & 5Why Analysis 


Term
What does Genichi Taguchi's Loss Function stiplulate? 

Definition
Genichi Taguchi's Loss Function stipulates that the total loss to society from poor quality increases in a geometric fashion as variability increases. Accordingly, products produced near the upper and lower specification are less "good" than products produced at the process target value, and there is little difference between products that are marginally acceptable and those that are marginally defective. 


Term
What's the essence of the Taguchi Loss Funtion? 

Definition
Producing parts closer to nominal and well within the specification limits yields a more robust and durable assembly  so all "good" parts are not created equal. 


Term
Use four target figures to demonstrate the difference between measurement precision and accuraccy. 

Definition


Term
A measurement system can be characterized in five ways: three in terms of location and two in terms of variation. 

Definition
Location (average measurement value)
Measurement Stability refers to the capacity of a measurement system to produce the same values over time when measuring the same sample.
Measurement Bias or Accuracy is a measure of the distance between the average value and true value.
Measurement Linearity is a measure of the consistency of Bias over the range of the measurement device.
Variation Repeatablity assesses whether the same appraiser can measure the same part/sample multiple times with the same measurement device and get the same value.
Measurement Reproducibility assesses whether different appraisers can measure the same part/sample with the same measurment device and get the same value. 


Term
A measurement system produces values whose average deviates from the true value. Its degree of deviation varies along the scale of the measurement, but is consistent over time at each point on the scale.How would you characterize the measurement problem? 

Definition
Measurement Bias and Linearity. 


Term
According to Taguchi's Loss Function, the loss to society from poor quality increases as a function of what?
AProcess Variability
BProcess Centering
CSpecification Limits
DInternal Scrap Rates 

Definition


Term
Which phase of the DMAIC process are "Histograms" primarily used? What are they used for? 

Definition
Histograms are primarily used in the Analyze phase of the DMAIC process and are a useful tool to describe a group of data. The primary goal of all Six Sigma projects is to reduce process variability and improve the consistency of output. Histograms provide a visual map of variability (dispersion or spread) so they help establish priorities for action.
Histograms show centering, spread (dispersion), and shape (relative frequency) of the data.
Histograms are very useful in the Measure, Analyze, and Improve phases of the DMAIC cycle. If you need to answer any of these questions, the histogram is an appropriate tool.
How variable is the output of the process?
Does process output fall within specifications?
Have improvement actions been successful in reducing variation? 


Term
Why are control limits set at +/3 standard deviations? 

Definition
+/3 standard deviation limits provide the best economic balance between false signals and no signals. 


Term
What is the basis of the theory of statistical process control? 

Definition


Term
Name the various types of control chart, including what type of data they are used with. 

Definition


Term
What question does the use of "rational subgrouping" answer? 

Definition
Can variation in this process be captured between subgroups?
How should we draw the subgroup samples?
Is there too much variation within subgroups (i.e., are control limits artificially wide?)? 


Term
XmR Charts can be used to answer what kind of questions? 

Definition
Is a process stable over time?
If a process is stable, how capable is it?
What is the effect of a process change on the average or range of the output characteristics?
How will I know if a process becomes unstable, or the capability changes over time? 


Term
Under what conditions are pCharts used? 

Definition
When you are working with attribute (discrete) data and you want to chart fraction defective when the sample size is variable or constrant (though usually greater than 50 data). The chart assumes that the process has a binomial distribution. 


Term
Under what conditions are npCharts used? 

Definition
When you are working with attribute (discrete) data and you want to chart the number of defective units when the sample size is constant (usually greater than 50). This chart assumes the process has a binomial distribution. 


Term
Under what conditions are cCharts used? 

Definition
When you are working with attribute (discrete) data and you want to chart the number of defects when the sample size is constant (though usuallyg greater than 50). This chart assumes that the process has a Poisson distribution. 


Term
nder what conditions are uCharts used? 

Definition
When you are working with attribute (discrete) data and you want to chart the number of defects per unit when the sample size is variable or constant. This chart assumes that the process has a Poisson distribution. 


Term
What does the Central Limit Theorem state? 

Definition
The Central Limit Theorem states that the distribution of sample means will tend to fallow a normal distribution even if the population that the samples are drawn from is not normally distributed.
While control chart constants are calculated using the assumption of a normal distribution, control charts are not very sensitive to the shape of the underlying distribution because control limits set at three standard deviations are relatively wide, 


Term
Can a process have a Cp in excess of one but still fail to consistently meet customer expectations? 

Definition


Term
How do the two capability indicies (Cp or Cpk and Pp or Ppk) differ in meaning? 

Definition
Capability analysis is performed when it is necessary to understand the ability of a process to meet requirements. Since performance to requirements is a fundamental question, capability analysis is a frequent activity in the Measure phase of the DMAIC cycle. Capability Analysis is also performed in the Improve phase to verify the effectiveness of actions that have been taken. Capability Analysis can be used to answer the following questions:
What is the potential of the process to meet customer requirements? (Cp, Cpk)?
What is the actual performance of the process relative to customer requirements (Pp, Ppk)?
How capable would the process be if it were perfectly centered on target? 


Term
What should be done 1st to improve process capability (Cpk)?
ATake actions to reduce common cause process variation.
BTake actions to address special cause process variation.
CTake action to center the process on the specification limits 

Definition
BTake actions to address special cause process variation, then
CTake actions to center the process on specification limits, then
ATake actions to reduce common cause process variation 


Term
A Six Sigma team is working on a project in the order entry area to improve order accuracy and reduce cycle time. The team wants to analyze the variability in cycle time. What tool should be used?
Trend Chart, Fishbone Diagram, Benchmarking, or His 

Definition


Term
A Six Sigma team of an insurance company has been working on a project to reduce the number of claim defects leading to denied claims. A control chart of claim denials is outofcontrol. What conclusion should the team draw from this condition? 

Definition
The process is unstable over time. 


Term
A Six Sigma team is working to reduce the frequency of medical errors, and wishes to track the number of errors per patient per day. The sample size of patients varies from day to day. Which type of attribute control chart should the team use? 

Definition


Term
A diagnostic lab chartered a Six Sigma team to reduce the frequency of samples with label problems. The team charts the percentage of samples with label problems. Volume is high and stable enough to assume constant sample size. Which type of chart? 

Definition


Term
A Six Sigma team works to reduce the amount of bad debts and tracks the $ amount of receivables over 90 days past due (XmR and ImR charts). The avg balance outstanding is $736,500. The Median Moving Range is $58,000. What's the UCL for the Indiv. Chart? 

Definition
UCL(X) = Xbar + (3.14xMedian mR)
$918,620 


Term
A Six Sigma team works to recduce the # of journal entry errors, which are delaying a monthly closing process. The team gathered data over time and wishes to track % erroneous entries using a p chart. If pbar is 0.036 and n=2,000, what's the UCL? 

Definition
UCL = pbar + 3Sqrt((pbar(1pbar))/n)
0.048 


Term
After implementing process improvement actions, an SPC chart of the process shows consistent variability about the mean on the Xbar chart, but the Rchart shows 8 points below the Rbar line. What' happening? 

Definition
The process variability is exhibiting less variability between observations (part to part). 


Term
An order processing operation has specifications 4.0 hrs +/ 1.0 hrs. The process mean is 4.2 hrs with a std dev of 0.25 hrs. The process is stable and normally distributed. What is the Cp and Cpk of the process? 

Definition
Cp = (53)/(6x0.25) = 1.33
Cpk = (54.2)/(3*0.25) = 1.07 


Term
A Six Sigma team wishes to calculate Cpk in order to assess the capability of an order entry process. The team has determined that the process data are not normally distributed (distribution skewed). What should the team do? 

Definition
Transform the data to more closely fit a normal distribution. 


Term
An SPC chart of a process has several recent points outside its LCL. The team has taken actions to move the process that way so the outofcontrol condition is a favorable shift. What should the team do to calcualte Cpk and assess process capability? 

Definition
Collect 20 additional points to confirm the process shift, confirm stability, then calculate Cpk from the data collected after the shift. 


Term
What is the purpose of the Analyze phase of DMAIC? 

Definition
Ultimately, the analysis that you perform is intended to identify and understand causal relationships, i.e., how does variable X (input) affect variable Y (output), so you can find the root cause of variation and reduce it. 


Term
What are the three primary categories of investigation in the Analyze phase of the DMAIC cycle? 

Definition
Analyze I: Characterize the process (What is the current state of affairs)?
Analyze II : Compare treatments (Which treatment, or action, is more effective?
Analyze III : Model the process (Understand relationships, how does X impact Y?) 


Term
Describe the path taken in root cause analysis. 

Definition
We start with general experience and through deduction try to draw specific conclusions, theories or hypotheses. Those hypotehses are then tested for "truth", and the results in turn alter our general understanding (induction). The loop continues to cycle through the process of deduction and induction until the hypothesis is confirmed. 


Term
What is the "Ishikawa Diagram" used for? 

Definition
The Cause & Effect, or Fishbone diagram was first used by Dr. Kaoru Ishikawa in 1943. This diagram is used to identify all of the contribution root causes likely to be causing a problem. It's usually used in the Analyze phase of the Six Sigma DMAIC process to understand the sources of process variablity. The Fishbone Chart is an initial step in the screening process. After identifying potential root causes, further testing will be necessary to confirm the true root cause(s). 


Term
After identifying the potential root cause(s), what is the team's most appropriate next step? 

Definition
Take action to confirm (test) that the potential root cause(s) is/are the true toot cause(s) before pursuing corrective action. 


Term
In Regression terminology what do the following terms mean: r, R, Rsquare? 

Definition
rPearson's correlation coefficient is a bivariate (2variables) measure of association and can take a value between 1 and +1.
Rmultiple correlation coefficient R expresses the degree to which two or more predictors are related to the dependent variable and can only assume values between 0 and 1.
Rsquaremeans the same thing whether you square r or R: it is the coefficient of determination and gives the amount of explained variation due to the reqgression equation. 


Term
Which is a primary use of Fishbone Cause and Effect Charts?
AProvide a project road map.
BQuantify relationships between inputs and outputs.
CIdentify potential root causes of variability
DCategorize process inputs by department 

Definition
CIdentify potential root causes of variability. 


Term
What is the purpose of a Scatter Plot Diagram and in what phase of the DMAIC cycle is it most frequently used? 

Definition
Visually display the relationship between two variables, Analyze 


Term
Which assumptions are common to both Ordinary Least Squares and Logistics Regression?
Error variance is constant across predictor levels
Error terms are normally distributed
Error terms are independent of each other 

Definition
Error terms are independent of each other. 


Term
Which statement is true, based on logistic regression model regarding the impact of age on job permotion: Logit(Promotion)=4.2+0.4*AGE.
Chances of being promoted decrease with age.
Chances of being promoted increase with age. 

Definition
The chances of being promoted increase with age.
Other false statements:
Promotions are caused by increasing age
Promotions are linearly related to age 


Term
The Power of a test answers the question: If the null hypothesis is false, what is the probability that the data from the experiment will reject the null hypothesis? What are the biggest factors affecting power. 

Definition
Power is the chance of finding a significant effect when one does exist. Naturally, a highpowered test is desirable. The biggest factors affecting power are: size of the effect(bigger> power, significance level (greater>power), sample size (greater>power) and the population standard deviation (lower>power) 

