This is a guide for companies or entities that want to learn more about the six sigma management approach. The six sigma management approach was designed to maximize manufacturing processes and eliminate manufacturing defects. It includes the use of a set of quality management methods, including statistics and mathematics, to maximize production efficiency. This guide can be useful for small businesses or other entities that want to learn more about the six sigma approach.
Six Sigma Management Guide This is a guide for companies or entities that want to learn more about the six sigma management approach. The six sigma management approach was designed to maximize manufacturing processes and eliminate manufacturing defects. It includes the use of a set of quality management methods, including statistics and mathematics, to maximize production efficiency. This guide can be useful for small businesses or other entities that want to learn more about the six sigma approach. 1 Six Sigma Management A Comprehensive Manager’s Guide Table of Contents Overview of the Origin and History of Six Sigma ................................................................1 Six Sigma Doctrine Affirmations .....................................................................................2 What Makes Six Sigma Different ....................................................................................2 Methods .............................................................................................................................2 DMAIC.............................................................................................................................3 DMADV ...........................................................................................................................3 Quality Management Tools and Methods used in Six Sigma..............................................4 Thought Process Map .........................................................................................................5 Implementation Roles ........................................................................................................5 Six Sigma identifies several key roles for its successful implementation. ......................6 The Origin and Meaning of the Term "Six Sigma Process" .................................................7 The Fundamental Objective of Six Sigma........................................................................7 Calculating the Cost and savings of Six Sigma Quality ....................................................8 Bank Deposits: A Black Belt Case Study ..............................................................................9 Sigma Costs and Savings ...................................................................................................11 References: .......................................................................................................................14 Overview of the Origin and History of Six Sigma Six Sigma is a business management concept that was introduced by Motorola. It is a registered service and trademark of Motorola, Inc. In 1986, Bill Smith designed the specifics of the style. It started off as a set of procedures The Six Sigma symbol designed to improve manufacturing processes and eliminate defects. As of 2006, Motorola reported over US$17 billion in savings by putting Six Sigma into practice.1 The name "Six Sigma" came from an array of statistics called process capability studies. At first the reference was to the ability of manufacturing processes to produce a high percentage of output that met specifications. The courses of action that function using "six sigma quality" over the short term are believed to produce long-term defect levels that are below 3.4 defects per million opportunities (DPMO). Six Sigma's inherent goal is to improve all practices to meet that level of quality or higher. The concept was triggered by six previous decades of quality improvement methodologies like quality control, TQM, and Zero Defects. It was based on the works of pioneers like Shewhart Deming, Juran, Ishikawa, Tagachi and others. Application of the concept was then broadened to include other kinds of business processes as well. In Six Sigma a defect is termed as anything that may possibly lead to customer dissatisfaction. The model continues to be widely used in a great many sectors of industry. The Six Sigma concept searches for ways to improve the quality of process outputs by recognizing and eliminating the sources of the shortcomings and the inconsistencies in manufacturing and business processes. Six Sigma employs a set of quality management techniques, including statistical processes. It builds a special infrastructure of people within the organization (“Black Belts”, “Green Belts”, etc.) who are experts in administering these techniques. Each Six Sigma project that is achieved by an organization is carried out by using a defined series of steps with quantified financial targets like reducing costs, or increasing profits. By the late 1990s, almost two-thirds of the Fortune 500 companies had started using Six Sigma initiatives with the intention of reducing costs and improving quality. Other early adopters of Six Sigma who achieved well-publicized success are Honeywell and General Electric. In recent years, some practitioners have combined Six Sigma ideas with the lean manufacturing concept to introduce a methodology called Lean Six Sigma. 1 Information source: http://en.wikipedia.org/wiki/Six_Sigma © Copyright 2015 Docstoc Inc. 1 Six Sigma Doctrine Affirmations Business and manufacturing practices have attributes that can be analyzed, measured, improved and controlled. Continuous efforts to achieve stable and predictable process results like those necessary for reducing process variations, are of vital importance to the success of the business. Realizing sustained quality improvement calls for commitment from the entire organization, and above all, from top-level management. What Makes Six Sigma Different The characteristics that make the Six Sigma initiative different from predecessors’ initiatives are: Six Sigma has a clear commitment to making decisions based on verifiable data, instead of on assumptions and guesswork. Six Sigma has a unique infrastructure made up of "Champions," "Master Black Belts," "Black Belts," etc. to lead and implement the Six Sigma ideology. Six Sigma projects provide a clear focus for achieving measurable and quantifiable financial returns. With Six Sigma, there is an increased emphasis on strong management and leadership with support that is passionate. Methods Six Sigma projects follow two project principles that come from Deming’s “Plan-Do- Check-Act Cycle”. The standards are made up of five phases. Each phase contains the acronyms DMAIC and DMADV. DMAIC is used for projects that have been designed to improve existing business processes. DMADV is used for projects intended to create new product or new process designs. © Copyright 2015 Docstoc Inc. 2 Six Sigma Management A Comprehensive Manager’s Guide DMAIC DMAIC project methodology includes five phases: 1. Define high-level project goals and the current process. 2. Measure key aspects of the current process and collect relevant data. 3. Analyze the data to verify cause-and-effect relationships. Determine what the relationships are, and attempt to ensure that all factors have been considered. 4. Improve or optimize the process based on data analysis, and using appropriate techniques. 5. Control to make certain that any deviations from goals are rectified before they result in defects. Set up pilot runs to ascertain: a. The processes capabilities and inadequacies. b. To confirm appropriate movement on to production. c. To confirm an established control of the control mechanisms. d. To verify a continuous monitoring of the entire process. DMADV DMADV project methodology, also known as DFSS (“Design for Six Sigma”) includes five phases: 1. Define design goals that are consistent with customer demands and with the policies of the enterprise. 2. Measure and identify CTQs (characteristics that are Critical To Quality), product capabilities, production process capability, and risks. 3. Analyze to devise alternatives, create a high-level design and evaluate design capability to select the best design. 4. Design details, optimize the design and plan for design verification. This phase may require simulations. 5. Verify the design, set up pilot runs, implement the production process and hand it over to the process owners Quality Management Tools and Methods used in Six Sigma As a part of the individual phases of a DMAIC or DMADV project, Six Sigma also uses various established quality-management tools. These tools are also used outside of Six Sigma. The 5 Whys is a question-asking technique that is used to explore the cause/effect relationships that underlie a certain problem. When administering the 5 Whys process, the ultimate goal is to determine a root cause of a defect or a problem. Example The following example demonstrates the basic process: The Problem: My car will not start. 1. Why? – The battery is dead. (first why) 2. Why? – The alternator is not working. (second why) 3. Why? – The alternator belt has broken. (third why) 4. Why? – The alternator belt was well beyond its useful service of life and has never been replaced. (fourth why) 5. Why? – I have not been maintaining my car according to the recommended service schedule. (fifth why, a root cause) The questioning for this example could be taken further to a sixth, seventh, or an even greater level. This would be legitimate, as the "five" in 5 Whys is not gospel; rather, it is hypothesized that five instances of asking why is usually enough to get to a root cause. The real key is to encourage the troubleshooter to avoid assumptions and logic traps and instead to trace the chain of causality in direct increments from the effect through any and all layers of abstraction to a root cause that still has some connection to the original problem. The history of the 5 Whys The technique was originally developed by Sakichi Toyoda and was later used by the Toyota Motor Corporation during the evolution of their manufacturing methodologies. It is an important part of the problem solving training that is administered as part of the induction into the Toyota Production System. Taiichi Ohno, the architect of the Toyota Production System, described the 5 whys method as "... the basis of Toyota's scientific approach ... by repeating why five times, the nature of the problem as well as its solution becomes clear." The tool has seen widely used outside of Toyota, and is now used by Kaizen, Lean Manufacturing, and Six Sigma. © Copyright 2015 Docstoc Inc. 4 Criticism of the 5 Whys The 5 Whys is a powerful tool for engineers or technically savvy individuals to help get to the true causes of problems. The process has been criticized by former managing director of global purchasing for Toyota, Teruyuki Minoura as being too basic a tool to analyze root causes to the depth that is needed to ensure that the causes are fixed. The reasons for the criticism include: The inability to go beyond the investigator's current knowledge. They are not able to find causes that they don't already know about. The lack of support necessary to help the investigators ask the correct "why" questions. The results aren't repeatable. Different people using 5 Whys come up with different causes for the same problem. The propensity for investigators to stop at the symptoms instead of going on to the lower level root causes. The tendency to isolate a single root cause, while each question may possibly elicit many different root causes These can be significant problems when the method is applied through deduction only. To avoid these problems, it is a good practice to verify the answer to the current “why” question on-the-spot and before moving on to the next why question. Thought Process Map A thought process map, also known as a TMAP or TPM, is commonly recognized as one of the first tools that should be employed for a process improvement project or for projects that fall under the methodology of Six Sigma, or Lean Manufacturing. In essence, a TMAP gives thoughts, ideas and questions at the beginning of the project in a very structured and visual way; and that is relevant to accomplishing a project goal. It helps a team or a person to recognize all of the information, and the progression through a project or a DMAIC process. It has various formats; and will change throughout the life of the project as information and data is added, deleted, or elaborated upon. It also serves as a useful tool for a project manager to identify actions and goals. Implementation Roles One key innovation of Six Sigma involves the "professionalizing" of quality management functions. Before Six Sigma, quality management in practice was largely relegated to the production floor and to the statisticians who were in a separate quality department. Six Sigma borrows martial arts ranking terminology to define a hierarchy (and career path) that cuts © Copyright 2015 Docstoc Inc. registered 5 across all business functions and develops a promotion path that goes straight into the executive suite. Six Sigma identifies several key roles for its successful implementation. Executive Leadership includes the CEO and other members of top management. They are responsible for setting up a vision for Six Sigma implementation. They also empower the other role holders with the freedom and the necessary resources that enable them to explore new ideas for breakthrough improvements. Champions take responsibility for Six Sigma implementation across the organization in an integrated manner. Executive leadership draws the champions from upper management. Champions also act as mentors to Black Belts. Master Black Belts, identified by champions, act as in-house coaches on Six Sigma. They devote 100% of their time to Six Sigma. They assist champions and guide Black Belts and Green Belts. Apart from statistical tasks, they spend their time ensuring that a consistent application of Six Sigma occurs across various functions and departments. Black Belts operate under Master Black Belts to apply Six Sigma methodology to specific projects. They devote 100% of their time to Six Sigma. They primarily focus on the project execution of Six Sigma, whereas Champions and Master Black Belts focus on identifying projects/functions for Six Sigma. Green Belts, the employees who take up Six Sigma implementation along with their other job responsibilities, operate under the guidance of Black Belts. © Copyright 2015 Docstoc Inc. registered 6 The Origin and Meaning of the Term "Six Sigma Process" The term "six sigma process" comes from the concept that if one has six standard deviations between the process mean and the nearest specification limit, as shown in the graphic, just about no items will fail to meet specifications. This is based on the calculation method employed in process capability studies. Capability studies measure the number of standard deviations between the process mean and the nearest specification limit in sigma units. As process standard deviation goes up, or the mean of the process moves away from the center of the tolerance, fewer standard deviations will fit between the mean and the nearest specification limit, decreasing the sigma number and increasing the likelihood of items outside specification. Graph of the normal distribution, which underlies the statistical assumptions of the Six Sigma model. The Greek letter σ (sigma) marks the distance on the horizontal axis between the mean, µ, and the curve's inflection point. The greater this distance, the greater is the spread of values encountered. For the curve shown above, µ = 0 and σ = 1. The upper and lower specification limits (USL, LSL) are at a distance of 6σ from the mean. Due to the properties of the normal distribution, values lying that far away from the mean are extremely unlikely. Even if the mean were to move right or left by 1.5σ at some point in the future (1.5 sigma shift), there is still a good safety cushion. This is why Six Sigma aims to have processes where the mean is at least 6σ away from the nearest specification limit. The Fundamental Objective of Six Sigma The fundamental objective of the Six Sigma methodology is the implementation of a measurement-based strategy that focuses on process improvement and variation reduction through the application of Six Sigma improvement projects. This is accomplished through the use of two Six Sigma sub-methodologies: DMAIC and DMADV. The Six Sigma DMAIC processes (define measure, analyze, improve, control) is an improvement system for existing processes 7 falling below specification and looking for incremental improvement. The Six Sigma DMADV process (define, measure, analyze, design, verify) is an improvement system used to develop new processes or products at Six Sigma quality levels. It can also be employed if a current process requires more than just incremental improvement. Both Six Sigma processes are executed by Six Sigma Green Belts and Six Sigma Black Belts, and are overseen by Six Sigma Master Black Belts. According to the Six Sigma Academy, Black Belts save companies approximately $230,000 per project and can complete four to 6 projects per year. General Electric, one of the most successful companies implementing Six Sigma, has estimated benefits on the order of $10 billion during the first five years of implementation. GE first began Six Sigma in 1995 after Motorola and Allied Signal blazed the Six Sigma trail. Since then, thousands of companies around the world have discovered the far reaching benefits of Six Sigma.2 Calculating the Cost and savings of Six Sigma Quality One of the most distinct differences between Six Sigma and other quality management systems is the link to business finances. The financial benefits of potential process improvement projects are quantified and used to help select and prioritize process improvement projects. They are re-evaluated during the analytical phase to ensure that the cost of the improvements suggested will be supported by the benefit of the project. The financial benefits are verified when the project enters the control for DMAIC, and verify for DMADV phases. The rigor associated with linking Six Sigma projects to business financials helps connect everyone within the business -- not just the quality department and related personnel. The entire organization, including the CEO, CFO, line managers, employees, and shareholders, looks to Six Sigma to increase cost savings, productivity, and incremental revenue. It also helps differentiate substantial process improvements from insignificant 'fluff' projects that have little long-term benefit for the business. Below are a few posts from fellow quality professionals discussing how best to link quality to finances. If you have a question or would like to make an additional comment, go to the information source referenced below: "During the Define and Measure phase, we highlight what the project is supposed to do and how it is supposed to do it. Most of the time, maybe due to human natural tendencies, the improve phase is already running at the back of everyone's minds. "To forecast financial savings, we try to follow suit that Tangible benefits - cost of project implementation = Financial benefits. 2 Information source: http://www.isixsigma.com/sixsigma/six_sigma.asp 8 "Under each category like tangible benefits, we try to break it further down to cost of sales, tax savings and all the financial jargon along with it. The cost of project implementation will be labor cost and all other liabilities that arises from doing the project. And with that, we try to give the most accurate forecast as we can during the D and M phase. "As the project goes along, there may be some changes and we update this forecast to be even more accurate and revise the financial plan for approval." Bank Deposits: A Black Belt Case Study In early 2000, dot-coms were all the rage. Any idea even remotely related to the ability to transact online was immediately funded. Consequently, many decisions were made quickly and without supporting data. Many of these decisions were made in error. Could Six Sigma have made a difference? This case study reviews how a Black Belt entered a dot-com transactional business, reviewed a process, and came to his own conclusions about process performance. Case Study: Online Banking The Black Belt began working at online bank, and his first project involved the process of how deposits were made to this bank. Since it was an "online" bank, there were no branches for customers to use. Instead, deposits were mailed using the United States Postal Service (USPS). Savings resulting from the lack of branches and tellers were passed along to the customer in the form of higher rates, free services, etc. Customer focus groups and surveys and indicated that the process of making a deposit is of critical importance to a customer. The process from the customer's viewpoint is very straightforward -- they sign a check, fill out a deposit slip, and mail both to the bank. Deposits were the second largest driver of inquiries to the customer call center (13% of all calls). Customers expressed frustration in mailing delays and couldn't understand why their checks took so long to post to their account. The Deposit Process The bank's mission was to receive the deposits as quickly as possible and begin the deposit and check clearing cycle. When the bank originally set up the processes, a decision was made to establish 'local' deposit locations around the United States. These local deposit locations received the deposits and overnight express reshipped them to a central processing location daily. 9 This local receipt and express reshipment to a central location was done for two main reasons: 1. A deposit being mailed to a local location would take less time than mailing to a centralized, national location. 2. Customer input indicated that mailing within a state or to a neighboring state would make customers more comfortable than mailing to a centralized, national location somewhere across the United States. The DMAIC Project The Black Belt hit the ground running. A project charter was created identifying exactly what the process entailed. The business case was written, the problem statement crafted and the scope clearly identified. The team was formed and quickly moved into the measurement phase. Data surrounding the deposits was collected and the analyze phase began to yield some alarming results. Intuition led the leaders of the business to set up a system that locally collected deposits for express reshipment to a centralized, national location for processing. How could mailing to a centralized, national location be quicker than mailing locally and express reshipping? Why wouldn't customers feel more comfortable mailing locally than to a centralized, national location? Data and Root Causes Data collection, pointed out a few flaws that had not been identified in the beginning: Because of USPS processes, some deposit mailings to 'local' deposit locations took as long as three days. Tack on a weekend stay for the above listed bullet, and you can see how a deposit made via mail to a 'local' deposit location may take longer than five days just to be received by the bank. For deposits that were received during the week, the express reshipment process functioned properly. On the weekend, however, express reshipment wasn't possible, so deposits arriving on Saturday were not express reshipped until Monday evening. The express reshipment process was manual. Manual processes that are not reinforced daily and that do not have adequate control plans tend to break down. That is exactly what occurred with the local deposit locations. Some locations wouldn't receive deposits on a daily basis. When deposits were received, they sometimes wouldn't be express reshipped that night because of a lack of engrained process. 10 Additional Findings An additional analysis of deposits made to a 'local' deposit location with express reshipment to a national location versus mailing directly to a centralized, national location yielded the following results: The 'local' process operates at a 2.1 sigma level, while the centralized, national process operates at a 2.5 sigma. A 2 sample t-test indicated that there is a statistically significant difference between the two process means (p=0.0013). The centralized, national process is faster (2.6 average days) than the local express reshipment process (4.6 average days). An additional survey conducted with focus groups indicated that the deposit mailing location is not a significant factor for a majority of respondents. As an aside, the original data indicating that customers were more comfortable mailing deposits within their state could not be found. A benchmarking analysis of direct competitors indicated that all utilized a centralized, national deposit process. Project Conclusions It didn't take further data collection to convince the leaders of the business to modify their deposit process and move to a centralized, national process. The facts spoke for themselves. Cost savings resulting from only printing one address envelopes (instead of numerous local), reduced overhead associated with processing, fewer customer inquiry calls and investigations, and a more stable process resulted in savings of $4MM per year. Not bad for a six month Black Belt project. Sigma Costs and Savings The financial benefits of implementing Six Sigma at your company can be significant. Many people say that it takes money to make money. In the world of Six Sigma quality, the saying also holds true: it takes money to save money using the Six Sigma quality methodology. You can't expect to significantly reduce costs and increase sales using Six Sigma without investing in training, organizational infrastructure and culture evolution. Sure you can reduce costs and increase sales in a localized area of a business using the Six Sigma quality methodology -- and you can probably do it inexpensively by hiring an ex- Motorola or GE Black Belt. I like to think of that scenario as a "get rich quick" application of Six 11 Sigma. But is it going to last when a manager is promoted to a different area or leaves the company? Probably not. If you want to produce a culture shift within your organization, a shift that causes every employee to think about how their actions impact the customer and to communicate within the business using a consistent language, it's going to require a resource commitment. It takes money to save money. How much financial commitment does Six Sigma require and what magnitude of financial benefit can you expect to receive? We all have people that we must answer to -- and rhetoric doesn't pay the bills or keep the stockholders happy (anymore). I was tired of reading web pages or hearing people say: "Companies of all types and sizes are in the midst of a quality revolution. GE saved $12 billion over “Companies of all types and five years and added $1 to its earnings per share. sizes are in the midst a Honeywell (AlliedSignal) recorded more than $800 quality revolution…. million in savings." "GE produces annual benefits of over $2.5 billion across the organization from Six Sigma." "Motorola reduced manufacturing costs by $1.4 billion from 1987-1994." "Six Sigma reportedly saved Motorola $15 billion over the last 11 years." The above quotations may in fact be true, but pulling the numbers out of the context of the organization's revenues does nothing to help a company figure out if Six Sigma is right for them. For example, how much can a $10 million or $100 million company expect to save? I investigated what the companies themselves had to say about their Six Sigma costs and savings -- I didn't believe anything that was written on third party websites, was estimated by "experts," or was written in books on the topic. I reviewed literature and only captured facts found in annual reports, website pages and presentations found on company websites. While recent corporate events like the Enron and WorldCom scandals might lead us to believe that not everything we read in a company's annual report is valid, I am going to provide the following information based on the assumption that these Six Sigma companies operate with integrity until proven otherwise. I investigated Motorola, Allied Signal, GE and Honeywell. I choose these four companies because they are the companies that invented and refined Six Sigma -- they are the most mature in their deployments and culture changes. As the Motorola website says, they invented it in 1986. Allied Signal deployed Six Sigma in 1994, GE in 1995. Honeywell was included because Allied Signal merged with Honeywell in 1999 (they launched their own initiative in 1998). Many companies have deployed Six Sigma between the years of GE and Honeywell.3 12 Table 1: Companies And The Year They Implemented Six Sigma Company Name Year Began Six Sigma Motorola (NYSE:MOT) 1986 Allied Signal (Merged With Honeywell in 1999) 1994 GE (NYSE:GE) 1995 Honeywell (NYSE:HON) 1998 Ford (NYSE:F) 2000 Table 2 identifies by company, the yearly revenues, the Six Sigma costs (investment) per year, where available, and the financial benefits (savings). There are many blanks, especially where the investment is concerned. I've presented as much information as the companies have publicly disclosed. Table 2: Six Sigma Cost And Savings By Company Year Revenue ($B) Invested ($B) % Revenue Invested Savings ($B) % Revenue Savings Motorola 1986-2001 356.9(e) ND - 16 1 4.5 Allied Signal 1998 15.1 ND - 0.5 2 3.3 GE 1996 79.2 0.2 0.3 0.2 0.2 1997 90.8 0.4 0.4 1 1.1 1998 100.5 0.5 0.4 1.3 1.2 1999 111.6 0.6 0.5 2 1.8 1996-1999 382.1 1.6 0.4 4.4 3 1.2 Honeywell 1998 23.6 ND - 0.5 2.2 1999 23.7 ND - 0.6 2.5 2000 25.0 ND - 0.7 2.6 1998-2000 72.3 ND - 1.8 4 2.4 Ford 2000-2002 43.9 ND - 1 6 2.3 Key: $B = $ Billions, United States (e) = Estimated, Yearly Revenue 1986-1992 Could Not Be Found ND = Not Disclosed Note: Numbers Are Rounded To The Nearest Tenth Although the complete picture of investment and savings by year is not present, Six Sigma savings can clearly be significant to a company. The savings as a percentage of revenue vary from 1.2% to 4.5%. And what we can see from the GE deployment is that a company shouldn't expect more than a breakeven the first year of implementation. Six Sigma is not a "get rich quick" methodology. I like to think of it like my retirement savings plan -- Six Sigma is a 3Information source: Six http://www.isixsigma.com/library/content/c020729a.asp 13 get rich slow methodology -- the take-away point being that you will get rich if you plan properly and execute consistently. As GE's 1996 annual report states, "It has been estimated that less than Six Sigma quality, i.e., the three-to-four Sigma levels that are average for most U.S. companies, can cost a company as much as 10-15% of its revenues. For GE, that would mean $8-12 billion." With GE's 2001 revenue of $111.6 billion, this would translate into $11.2-16.7 billion of savings. Although $2 billion worth of savings in 1999 is impressive, it appears that even GE hasn't been able to yet capture the losses due to poor quality -- or maybe they're above the three-to-four Sigma levels that are the average for most U.S. companies? In either case, 1.2-4.5% of revenue is significant and should catch the eye of any CEO or CFO. For a $30 million a year company, that can translate into between $360,000 and $1,350,000 in bottom-line-impacting savings per year. It takes money to make money. Is investing in Six Sigma quality, your employees and your organization's culture worth the money? Only you and your executive leadership team can decide the answer to that question. References: 1. Motorola Six Sigma Services. Motorola University. 22 July 2002 <http://mu.motorola.com/sigmasplash.htm>. 2. AlliedSignal Inc. 1998 Annual Report. Honeywell Inc. 22 July 2002 <http://www.honeywell.com/investor/otherpdfs/ALD98.pdf>. 3. GE Investor Relations Annual Reports. General Electric Company. 22 July 2002 <http://www.ge.com/company/investor/annreports.htm>. 4. Honeywell Annual Reports. Honeywell Inc. 22 July 2002 <http://investor.honeywell.com/ireye/ir_site.zhtml?ticker=HON&script=700>. 5. Better Understand Six Sigma Plus With Honeywell's Special PowerPoint Presentation. Honeywell Inc. 22 July 2002 <http://www.honeywell.com/sixsigma/page4_1.html>. 6. Quality Digest, "Six Sigma at Ford Revisited", June 2003, p. 30. <http://www.qualitydigest.com/june03/articles/02_article.shtml>. 14
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