Six Sigma Final Exam

You should always invest in stop-and-fix systems, even if you don't have a problem-solving process in place with people following it.

FALSE

Which is the correct formula for the calculation of the overall standard deviation of a data set?

III only (sqrt over all - epsilon (xi-xbar)2/(n-1))

According to the author of The Toyota Way, the reason Toyota is the best learning organization he has seen is that it sees _____________________________ as two sides of the same coin, melding them in a way that creates great continuity.

standardization and innovation

Which type of process map is constructed FIRST in a DMAIC improvement project?

"As Is" or "Current State" process map, showing how the process works today

To enable its growth into an international company, Toyota has developed remarkably fast methods for transmitting its operations culture and practices into diverse countries and cultures.

FALSE

Toyota relies on a single framework/philosophy for motivating its employees.

FALSE

Complete the statement: Kanban is ...

... not an ideal, but an acceptable alternative when one-piece flow cannot be implemented.

Measurements taken from a critical work process are observed to be normally distributed. The average of the measurements is 10 and the standard deviation is 2 If the process continues to behave the same, what is the probability of observing a measurement less than 4?

0.3%

Select all the statements that are TRUE about applying Lean and the Toyota Way to a service, technology, or transaction company.

1 The work in service/technology/transaction companies is usually more difficult to "see." So simply taking steps to make the work visible in these companies typically leads to quick improvements. 2. Kaizen workshops can be conducted at service/technology/transaction companies to improve targeted areas. FALSE: There is less waste in services/technology/transaction companies, so efforts to implement Lean or the Toyota Way need to be extended to account for slower progress. Executive support is not as needed at service/technology/transaction companies.

Select all the phrases below that correctly complete the statement, "Capability is ..."

1. ... connected with process/product cost; a higher capability process/product will be less wasteful than a lower capability process/product. 2. ... a comparison of the "voice of the customer" to the "voice of the process." 3. ... a quantitative assessment of how well process/product performance matches customer requirements for that process/product. NOT: ... a yes/no assessment; a process/product is either capable or it is not, ... not important to consider during the design stage of a process or product, ... more qualitative than quantitative.

Which statements about 5S below are TRUE?

1. 5S works in both manufacturing and service environments. 2. 5S consists of Sort, Straighten, Scrub, Standardize, and Sustain. 3. 5S is intensely visual. FALSE: Management is not a critical player in the sustained success of 5S.

Six Sigma can be defined as... (Select all that are true.)

1. A problem-solving methodology 2. A specific level of quality employed by Motorola NOT: The sixth iteration of the quality system invented by Toyota

Which of the statements below about Control Charts are TRUE?

1. Control charts graphically communicate the Voice of the Process (VOP). 2. A control chart's control limits are at a level corresponding to 99.7% probability. 3. Control charts are used to detect the presence of special causes acting in a process. FALSE: Control charts graphically communicate the Voice of the Customer (VOC).

Match each intended chart use on the left with the chart type/name on the right.

1. Dot Plot/Histogram: To review the details of how the variation in the data is distributed and shaped. 2. Box/Whisker: To compare the variation and location of two or more sets of data, side-by-side. 3. Scatter Plot: To explore possible relationships between two or more variables. 4. Time history/process behavior chart: To explore how the variation in a set of data has played out over the sequence it was observed.

Identify all of the reasons below for why charts or graphs should be used in the initial analysis and reporting of data.

1. Graphs and charts are better at quickly communicating information to an audience. 2. Graphs and charts of data provide necessary context. 3. Graphs and charts allow "signals" to be quickly detected in the data. NOT: It's basically unavoidable to include charts and graphs, since these tools are built into every data analysis software.

Select the statements regarding Heijunka which are TRUE:

1. Heijunka creates some waste, but overall it eliminates far more waste. 2. Heijunka involves leveling both mix and volume. 3. A company should create approximately level production prior to attempting to standardize work.

Which are control charts for continuous data?

1. I-{MRbar} Chart 2. {Xbar} - S Chart 3. {Xbar} - R Chart

Select all the statements about residuals that are TRUE:

1. If a line model is a valid fit, its residuals will be normally distributed. 2. If a line model is a valid fit, the level of variation in the residuals will be approximately constant across the range of the fitted line. FALSE: Residuals are the difference between the X and Y values for each pair in the data set.

Select all the statements from below that are TRUE about Hansei.

1. Includes the idea of recognizing individual responsibility. 2. Is often described as "reflection." 3. It is really being honest about your own weakness. 4. Properly performed, involves contrition for what went wrong. 5. The objective is not to hurt the individual but to help that individual improve--not to hurt the program but to show flaws to improve the next program. FALSE: Has been relatively straightforward for Toyota to transfer to its business units outside Japan.

Mark all the statements that are TRUE regarding Toyota's decision making approach.

1. Is based in nemawashi, a Japanese cultural approach to reaching consensus and change. 2. Considers "sets" of alternatives at one time, rather than zeroing in on a preferred solution. 3. Can be summarized as "make decisions slowly by consensus" FALSE: Goes fast at first, but then slows at the end as critical information is compiled.

When using Excel to fit a line to a set of paired data, always make sure to have the line's Y-axis intercept pass through zero.

FALSE

Which of the following are benefits or advantages gained from the work of mapping out a process?

1. It enables you to "see" the flow and sequence of the work 2. You create an "baseline" or foundation upon which you can frame discussions about the work being performed 3. You gain previously unknown insights into the nature and challenge of the work

Mark all the statements below that are TRUE regarding Genchi genbutsu.

1. Literally translated, Genchi means the actual location and genbutsu means the actual materials or products. 2. Is synonymous with the more popular term gemba. FALSE: An "Ohno circle" is a tool used to contain or cordon off a production area producing defective parts. Is not applied to executives at Toyota.

Select ALL the statements below that are TRUE:

1. Long-term variation includes the effect of both common causes AND special causes. 2. Short-term variation is associated with common causes. 3. When calculating the short-term standard deviation using the interpoint range method, it is critical to make sure the data points are listed in the exact sequence in which they occurred in reality. 4. The short-term standard deviation represents how consistently a process will perform under a duration of best conditions. NOT: Theoretically, if special causes are present in a system, the long-term standard deviation will be less than the short-term standard deviation.

Which statements are TRUE regarding the overall "Toyota Way" of operating a business?

1. More than expertly using specific Lean tools, Toyota's success is ultimately based on it ability to cultivate leadership, teams, and culture, to devise strategy, to build supplier relationships, and to maintain a learning organization. 2. The 4 Ps of Toyota's way of operating a business are: sticking to a long-term PHILOSOPHY; eliminating waste from PROCESSES; respecting, challenging, and growing PEOPLE and PARTNERS; and continuously improving and solving PROBLEMS. FALSE: It is NOT aligned with conventional thinking and is NOT straightforward.

Match each customer requirement definition, on the left, with its type name, on the right.

1. Needs: The requirements that are so basic to the customer that they do not even state them. 2. Wants: The stated requirements that incrementally add (or detract) from the customer's satisfaction proportional to the degree they are met (or not met). 3. Delighters: The requirements that are so surprisingly good to the customer that they are not aware of them before seeing them.

In the diagram below, the measured performance of parts on a characteristic that is critical to the customer's experience is shown. (Part 2 is out of the allowable specification by the smallest possible margin and part 3 is within the allowable specification by the smallest possible margin.) Considering the four parts shown in the diagram, select all true statements about the parts' life cycles.

1. Part 1 (under LSL) will end up costing the producing company the most of the four parts. 2. Part 4 (just under target) will end up costing the producing company less than the other three parts NOT: Part 2 (under LSL) will end up costing the producing company much more than part 3 (just over LSL)

If the top leadership of the organization you're in is not committed to a long-term improvement plan, which of the choices below is listed as a viable option by the author of The Toyota Way:

1. Participate in playing the game of applying tools for short-term gains and hope you share in the gains. 2. Find greener pastures. 3. Work to build a successful lean model and educate top management by blowing them away with exceptional results. FALSE: Publicly rebuke top management to pressure them into adopting a long-term approach.

Which of the statements below about Poka-Yoke are TRUE?

1. Poka-Yoke sometimes targets detection of mistakes before they impact the customer. 2. Poka-Yoke is one of the simplest tools to master. 3. Poka-Yoke sometimes targets prevention of a mistake. FALSE: Poka-Yoke most often requires adding technology.

Select all the statements about the coefficient of determination (R) that are true:

1. The coefficient of determination (R) can range from 0 to 1. 2. The coefficient of determination (R) tells you what proportion of the observed variation is described by the fitted line. 3. The coefficient of determination (R) is equal to the square of the correlation coefficient (r). FALSE: The coefficient of determination is the ratio of the regression line coefficients

Select all the statements about RTY below that are TRUE.

1. The concept of RTY validates the idea of reducing process steps or part count to improve quality. 2. Calculated RTY is never greater than its lowest-yield component. 3. For a product with three critical characteristics, each with a FTY of 20%, the calculated RTY is 0.8%

Which of the following statements regarding Toyota's approach to eliminating waste are TRUE?

1. The eighth category Toyota considers as waste is "unused employee creativity." 2. Toyota's approach to reducing waste differs from traditional process improvement by considering removing/reducing non-value-adding steps instead of just focusing on optimizing value-adding steps. 3. Toyota's method for detecting waste starts with examining the manufacturing process from the customer's perspective. FALSE: Toyota communicates its waste elimination approach using the analogy of a house, because a house conveys permanent strength and the ability to withstand external forces (competition).

Mark all the statements below that are TRUE regarding how Toyota views and treats its suppliers and partners.

1. Toyota is very careful when deciding what to outsource and what to do in-house. 2. Toyota often assigns a jishuken (learning) project to its suppliers to challenge the supplier and provide them an experience for learning. FALSE: Toyota challenges its suppliers by expecting them to figure things out on their own. Toyota leverages its suppliers to achieve short-term gains.

Which of the following statements regarding the history of Toyota are TRUE?

1. Toyota's early leaders where influenced by their observations/studies of Henry Ford's automobile production practices. 2. Toyota had its origins in building better looms. FALSE: There is a long legacy at Toyota of operations leaders expertly detecting and resolving problems using reports and remote methods.

Correlation coefficient (r)

1. indicates whether the relationship between the variables is positive or negative. 2. indicates the strength of certainty of the relationship between the variables. 3. can range from -1 to +1

Which are control charts for attribute data?

1. u chart 2. p chart

Chart points that are abnormally close to the centerline or to a control limit line.

Hugging

The time it takes to complete a critical business process has a customer requirement to be no longer than 10 minutes. Recent data from this process shows its performance is normally distributed, with an average of 8 minutes and a short-term standard deviation of 1 minute. Using the table below, what is the expected rate, over the long-term, for this process exceeding its requirement limit? ZST DPMOLT 0 933,193 1 691,462 2 308,538 3 66,807 4 6,210 5 233 6 3.4

308,538

Calculate the First Time Yield for a process that starts with 100 items, successfully reworks/corrects 30, scraps 10, and eventually delivers 90 completed items.

60%

How much improvement has typically been achieved in six sigma projects?

70%

For the following data set, calculate the median: 8, 19, 9, 10

9.5

For normal data, what is the probability of a data value occurring between +/- two standard deviations of the average?

95%

Which element should NEVER be included in a project problem statement?

An indication of the probable cause of the problem.

Which element should NEVER be included in a project objective statement?

An indication of the solution direction.

Match each waste description with its correct Lean term:

Any of the eight types of waste: Muda Waste due to unevenness: Mura Waste due to overburden: Muri

A car company inspects each newly manufactured car to determine if it is "acceptable" or "defective" prior to shipping. If you were reviewing the recorded final conclusions from 100 of these assessments, what type of data would you be working with?

Attribute

One or more chart points exceeding the process control limits.

Beyond Control Limits

At a different car company, each finished car is inspected and a count of the number of defects found is recorded. If you were reviewing the recorded number of defects found on each of a group of 100 cars, what type of data would you be working with?

Continuous

Match each six sigma role with the correct description of its responsibilities:

Core leadership team member: Planning the strategic intent of the company's six sigma efforts; connects the six sigma efforts to the executive team of the company. Deployment leader: Leading and managing the work of rolling six sigma out to organizations and individuals within the company. Champion: Leading and advocating for the methods, tools, and successes of six sigma within a company. Master Black Belt: an expert teacher Black Belt: The leader of a technically substantial improvement project; a trained practitioner up to the level of advanced methods and tools within six sigma. Green Belt: trained leader of an improvement Yellow Belt: an improvement project team member

Select the correct abbreviation for each capability index defintion.

Cp: The short-term capability, disregarding the location of the process average. Cpk: The adjusted short-term capability, discounted for the location of the process average. Pp: the long-term capability, disregarding the location of the process average. Ppk: The adjusted long-term capability, discounted for the location of the process average

Chart points which show the same pattern over equal periods of time.

Cycle

Match each phase of the Six Sigma improvement project roadmap (DMAIC) with its correct description on the right.

Define: Set the context, key metrics, and objectives for the project. Measure: Capture the current baseline performance and capability of the process or system being improved. Identify: all possible contributing factors. Analyze: Narrow the pool Improve: Develop and validate Control: Establish plans and procedures

Which list contains the five pillar principles of lean six sigma and using data?

Determinism, variation, measurement, leverage, risk

The best way for an employee to create a process map is by themselves, without distraction from other departments in the company.

False

Choose the answer that correctly fills in the blank in the following statement: Standardized tasks are the ________________ for improvement and employee empowerment.

Foundation

Discipline employees for attendance or other reasons.

Group leader

Report and track daily production performance to goals.

Group leader

Which of the following are the usual six categories used to start a fishbone (Ishikawa) diagram?

Man, Measurement, Materials, Method, Environment, Machine

Six Sigma can be valuable applied in which of the following domains:

Managing, Process Improvement, Design, Thinking

Which of the following statements about creating continuous process flow are TRUE?

One-piece flow creates real flexibility. The intent of working towards the ideal of single piece continuous process flow is to reveal previously unseen waste. One-piece flow improves safety. One-piece flow builds in quality. One-piece flow creates higher productivity. The waste associated with "batch and queue" production is the result of individual departments optimizing their own work to the detriment of the overall production flow. One-piece flow improves employee morale. FALSE: Operations problems and pains simply disappear by creating one-piece flow cells. One-piece flow requires greater floor space. One-piece flow increases inventory costs.

Referring to the diagram below, which of the four parts shown would the customer prefer to have? (Part 2 is out of the allowable specification by the smallest possible margin and part 3 is within the allowable specification by the smallest possible margin.)

Part 4 - closest to target value NOT: Parts 1-3

Select the correct term for each provided measurement system definition below.

Resolution: The smallest increment a measurement provides. Accuracy: How closely the average of repeated measurements is aligned with the true, real value. Precision: How tightly repeated measurements are grouped. Repeatability: The part of measurement system variation that occurs when you repeat measurements with the same item, the same setup, and the same equipment, under similar environmental conditions; the short-term variation in a measurement system. Reproducability: The part of measurement system variation that occurs when you repeat measurements with the same items but with different measurement setups, different inspectors, or under different environmental conditions; the long-term variation in a measurement system.

Too many chart points in a row all on one side of the process average.

Run

A learning organization is one that continuously learns how to learn.

TRUE

Asking 5 Whys enables you to take countermeasures at the deepest level of cause that is feasible and at the level that will best prevent recurrence of the problem.

TRUE

Flow where you can, pull where you must.

TRUE

Hoshin Kanri is a method for creating aligned goals across the hierarchy of an organization.

TRUE

In regression, the total squared error (SSTO) is equal to the squared error due to the regression coefficients (SSR) plus the squared error due to the noise around the fitted line (SSE).

TRUE

One characteristic of Toyota's leadership is that it develops leaders and promotes from within to foster a constancy of purpose over time.

TRUE

Solving quality problems at the source saves time and money downstream.

TRUE

Toyota looks at technology as a tool that, like any other tool, exists to support the people and the process.

TRUE

True problem solving requires identifying "root cause" and not just "source."

TRUE

Insure that standardized work is followed.

Team leader

Respond to andon calls by Team Members.

Team leader

Carry out work according to the current standard.

Team member

Continually look for improvement opportunities in the work and work standard.

Team member

The closer your work can match the ideal of single piece flow, the less waste your work will have.

True

A continuous measurement system has been analyzed and the ratio of the measurement system variation to the overall observed variation is calculated as follows: variance measure/variance observed = 0.7

This is an unacceptable measurement system. Decision errors will be made using this system.

What is the stated purpose for setting up a "pull" production system?

To avoid overproduction

Too many chart points either consecutively increasing or decreasing.

Trend

A DPO measurement from one process can be validly compared to the DPO of another.

True

Are these the correct steps and sequence for performing an FMEA on a process? List the process steps List the failure modes for each process step List all the effects of each failure mode Score the severity of each effect List the causes of each failure mode List the likelihood of occurrence (the frequency) of each cause Score the occurrence of each cause List the current controls or detection methods for each cause Score each control/detection method For each row, multiply the severity, occurrence, and detectability scores together to calculate a Risk Priority Number (RPN)

True

"VSM" is an acronym that stands for:

Value Stream Map

Identifying a key output variable that can be measured is _______________ to an improvement project.

critical