Giới thiệu về phương pháp lean six sigma

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GIỚI THIỆU

Để tránh bất kỳ sự nhầm lẫn nào, hãy bắt đầu bằng cách đưara các định nghĩa hoạt động cơ bản của chúng ta về Lean, SixSigma và Lean Six Sigma.

- Lean: Phương pháp Lean là một triết lý hoạt động tập trung vàoviệc xác định và loại bỏ tất cả lãng phí trong một tổ chức. Cácnguyên tắc tinh gọn bao gồm không tồn kho, ln chuyển hàngloạt, cắt giảm kích thước lơ, cân bằng dây chuyền, không thờigian chờ đợi, hệ thống kiểm sốt sản xuất kéo thay vì đẩy, bố tríkhu vực làm việc, nghiên cứu thời gian và chuyển động cũng nhưthời gian chu kỳ cắt. Các khái niệm này được áp dụng cho các ứngdụng sản xuất, hỗ trợ và dịch vụ. Lean tập trung vào việc loại bỏlãng phí khỏi các quy trình và tăng tốc độ xử lý bằng cách tậptrung vào những gì khách hàng thực sự coi là chất lượng và làmviệc ngược lại từ đó.

- Six Sigma: Phương pháp Six Sigma là một chiến lược quản lýkinh doanh được thiết kế để cải thiện chất lượng đầu ra của quytrình bằng cách giảm thiểu sự biến đổi và nguyên nhân gây ra lỗitrong quy trình. Nó là một tập hợp con của phương pháp TQM tậptrung nhiều vào các ứng dụng thống kê được sử dụng để giảm chiphí và cải thiện chất lượng. Nó thiết lập một cơ sở hạ tầng đặcbiệt trong tổ chức được đào tạo đặc biệt về các phương phápthống kê và các phương pháp tiếp cận giải quyết vấn đề, đóng vaitrị là chuyên gia trong các phương pháp này. Hai phương pháptiếp cận mà các chuyên gia này sử dụng trong các hoạt độngphân tích vấn đề và giải pháp của họ là Define, Measure, Analyze,

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Improve, and Control (Xác định, Đo lường, Phân tích, Cải thiện vàKiểm sốt (DMAIC)) và Define, Measure, Analyze, Design, andVerify (Xác định, Đo lường, Phân tích, Thiết kế và Xác minh(DMADV)).

Six Sigma nhằm mục đích loại bỏ sự biến đổi của quy trình và cảitiến quy trình dựa trên định nghĩa của khách hàng về chất lượngvà bằng cách đo lường hiệu suất quy trình và tác động của thayđổi quy trình.

- Lean Six Sigma (LSS): Phương pháp LSS là một triết lý hoạt độngtrên toàn tổ chức, kết hợp hai phương pháp cải tiến hiệu suất phổbiến nhất hiện nay: phương pháp Lean và phương pháp SixSigma. Mục tiêu của những cách tiếp cận này là loại bỏ chín loạilãng phí (được phân loại là khiếm khuyết, sản xuất thừa, vậnchuyển, chờ đợi, tồn kho, di chuyển, xử lý quá mức, nhân viênkhông được sử dụng đúng mức và lãng phí hành vi) và cung cấphàng hóa và dịch vụ với tỷ lệ 3,4 lỗi trên một triệu cơ hội. (DPMO).

Lưu ý: Six Sigma, Lean và LSS đều là các phương pháp chứamột số công cụ, kỹ thuật và khái niệm được thiết kế để cải thiệnhiệu suất của tổ chức.

Trong suốt cuốn sách này, để phù hợp với thông lệ, phươngpháp Six Sigma, phương pháp Lean và phương pháp LSS cũng sẽđược gọi là Six Sigma, Lean và/hoặc LSS.

Điều quan trọng cần lưu ý là các phương pháp Six Sigma,Lean và LSS đều là những triết lý/chiến lược hoạt động trên toàntổ chức với trách nhiệm giải trình và trọng tâm chiến lược. Giá trịthực sự của LSS bắt đầu thể hiện khi nó được tích hợp với kế

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hoạch chiến lược của tổ chức, giúp thực hiện kế hoạch đó tậptrung vào khách hàng sử dụng cuối. Để đạt được lợi ích thực sựcủa LSS, các dự án sẽ vượt qua ranh giới tổ chức và tập trung vàoquy trình kinh doanh. Kết quả chiến lược bền vững có thể đạtđược khi điều này được thực hiện. Khi áp dụng vào một quy trìnhkinh doanh, những lợi ích thu được sẽ đưa tổ chức hướng tới hiệusuất đẳng cấp thế giới trong quy trình kinh doanh đó.

Trọng tâm của tất cả các chương trình LSS thành cơng là cơsở hạ tầng hiệu quả giúp chuyển các mục tiêu chiến lược và lĩnhvực hoạt động của tổ chức thành các kế hoạch hành động ngắnhạn cụ thể nhằm tối đa hóa giá trị và cung cấp khả năng quản trịvà quản lý phù hợp, cùng với việc giám sát kết quả

LSS Cultural Building Blocks

All too often these methodologies are treated as a group of toolsto be applied rather than a new cultural behavioral pattern thatstarts with the executive team. Too much focus has been appliedto teaching the tools related to these methodologies in a two-level focus on embedding the Lean and Six Sigma cultures intothe organization. As a result, these initiatives are often treated asprojects where people are trained, problems are solved, and theimmediate problem is put to bed while the organization goes backto business as usual. When this occurs, savings are short-livedand the problems that were put to bed soon wake up and have tobe addressed again and again.

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The person who makes the LSS methodology a success within anorganization is not an LSS Black Belt (LSSBB) or even an LSSMaster Black Belt (LSSMBB). The people who make LSS a successare the executives who will not be satisfied with any waste withinthe organization and who won’t allow anything but exceptionallygood products and services to be provided within or as outputfrom the organization he/she is responsible for. It is the executivewho doesn’t have excellence as a goal, but as a standard oftoday’s performance for himself/herself and everyone withinhis/her organization, who is the ideal role model for theorganization.

These are hard requirements to meet, but it’s what is required tobe successful in today’s highly competitive environment. LSSGreen Belts (LSSGBs) and LSSBB can bring about significantchanges and improvement in organizational performance, butthese gains often last for only a short period of time unless thereis a significant change in the fundamental culture within theorganization. Business excellence in an organization encompassesthe areas of strategic focus or intent, customer loyalty/advocacy,employee delight, and seamless process integration. All thebusiness excellence models like Malcolm Baldrige, EFQM, etc.,have these areas incorporated in their models in different ways.This handbook clearly shows how these tools, along with theanalysis/reduction of constraints, inventive problem solving, andthe importance of human behavior modifications like applied

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behavior analysis, among others, can be used effectively to buildupon the shoulders of the TQM and quality managementprograms of the past.

Connecting the Tools with Engineering Goals

Each of the LSS tools has been often connected with well-knownengineering goals, including cause-effect analysis, variabilityreduction, bottleneck reduction, waste reduction, and the theoryof inventive problem solving, which has its roots in TRIZ. In fact,many of the tools have had their beginnings in the TQM programsof 20 years ago, which was adopted by a majority of the Fortune1000 companies, a statistic that was validated by our 2002survey, which showed that over 80% of the Six Sigma approacheswere carryovers from the TQM methodology.

WHAT CAME FIRST—SIX SIGMA OR LEAN?

It may surprise you to learn that Lean came before Six Sigma.Since the very earliest production systems management hasfought to eliminate waste. Near perfection, on the other hand,was not a requirement for most consumers. Functionality for mostconsumers was the meet requirements quality standard thatprovided the maximum value (cost versus quality) to theconsumer. The father of the Lean Production Systems, as weknow them today, was Henry Ford Sr. There are very few of ourproducts and methodologies that are truly breakthrough

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approaches. Almost all of our approaches are evolutionary ratherthan revolutionary. The Lean approach was born in the early1990s with F.B. Gilbreth’s time and motion studies, where hebelieved that there was one best way of doing everything. This, inconjunction with Henry Ford Sr.’s Lean Production System, startedthe Lean focus. Toyota made use of this as a foundation andimproved upon it to develop Toyota’s manufacturing system.Today’s approaches to Lean are based upon Toyota’s verysuccessful manufacturing system.

In 1974 Motorola sold its TV production and design facilities toMatsushita, a Japanese manufacturer. Motorola had been one ofthe early developers of the TV concepts and one of the leadingmanufacturers under the brand name of Quasar Electronics, Inc. Itpromoted its TV as a TV with the work-center drawer for easyrepair. Matsushita restructured the manufacturing process,applying Total Quality Control to it. As a result, internal andexternal defect rates and cost were decreased significantly. (SeeFigure 1.1.)

This major turnaround in the Quasar brand name reflected poorlyon Motorola’s reputation. In addition, Motorola’s other operationswere losing market share at a very rapid rate. In 1981, William J.Weisz, Motorola’s COO, directed that all processes within thecompany should show a 10-fold improvement within 5 years. Todo this, Motorola embraced the TQM concept. In 1986 Weisz

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required all measurements to improve by a factor of 10, this timein just 3 years. This called for a radical change in the wayMotorola’s processes functioned. To bring about such a drasticchange, Motorola implemented what it called the Six SigmaProgram. The program set an objective for all processes tostatistically perform at an error rate no greater than 3.4 errors perdefect per million opportunities. Six Sigma Quality becamepopular in the United States immediately following Motorolawinning the 1988 Malcolm Baldrige National Quality Award. Theinformation package that Motorola distributed to explain itsachievements stated: “To accomplish its quality and totalcustomer satisfaction goals, Motorola concentrated on several keyoperational initiatives. At the top of the list is Six Sigma Quality, astatistical measure of variance from a desired result. In concreteterms, Six Sigma translates into a target of no more than 3.4defects per million opportunities. At the manufacturing end, thisrequires robust designs that accommodate reasonable variationin component parts while providing consistently uniform finalproducts. Motorola employees record the defects found in everyfunction of the business and statistical technologies are madepart of each and every employee’s job.”

FIGURE 1.1

Results of TQC on Quasar’s performance.

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Also during the early 1990s Motorola’s Six Sigma methodologywas gaining momentum, as GE was promoting it as one of itsmajor improvement drivers. Although Six Sigma was originallydesigned as an approach to reduce variability, qualityprofessionals and consultants added to the basic statisticalapproaches a number of additional techniques that focus onprocess improvement. (See Appendix C for a list of Six SigmaGreen Belt tools.)

Motorola’s initial focus was on reducing variation in a singlemeasurement. (See Figure 1.2.) Although the concept of focusingon reducing variation was a sound one, Motorola continued to losea major portion of its market share. By the time GE embraced SixSigma, it realized that the major gains from a performanceimprovement initiative would be reached by focusing onstreamlining the processes by reducing cost and cycle time. As aresult, the Six Sigma program was expanded to focus on settingnew levels of performance. (See Figure 1.3.)

FIGURE 1.2

Results of focusing on variation reduction.text

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With the economy in the United States changing from aproduction to a service economy, the focus on performanceimprovement transferred from the manufacturing process to theservice and support areas in the early 1980s. This resulted in agreat deal of focus on reviewing the support and serviceprocesses and redesigning them to make them more efficient,effective, and adaptable. Process redesign methodologies rootsstem from the poor-quality cost studies that IBM conducted in theindirect (support) areas during the 1970s. This evolved into thebusiness process improvement methodologies that theydeveloped during the early part of the 1980s. These approacheswere further defined and developed by Ernst & Young and

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published in the 1991 book entitled Business ProcessImprovement—The Breakthrough Strategy for Total QualityProductivity and Competitiveness, published by McGraw-Hill, NewYork.

Additional depth was added to the process improvement focuswhen Michael Hammer and James Champy published their 1993book entitled Reengineering the Corporation, published by HarperBusiness, New York. The basis of these methodologies was theelimination of no-value-added (NVA) activities from these criticalbusiness processes. These approaches, which were developed toredesign or re-engineer processes, became key building blocks inthe Six Sigma methodology during the 1990s.

The end result is that over the years Lean and Six Sigma havebeen viewed and utilized as distinctly separate methodologies toanalyze and improve processes. Rather than employing themseparately, however, many process gurus now advocate a mergerof the two for more dramatic process improvement. While weagree that this merger or marriage is valid, project leaders ofprocess improvement efforts that forcibly combine the twomethodologies without understanding what they are trying toimprove will achieve limited success. In the final analysis, processprofessionals must first understand their level of process maturityto choose the appropriate blend of Lean and Six Sigma methods

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and tools, and employ some type of hierarchy or Belt System tohelp make the marriage last.

TECHNICAL COMPETENCY LEVELS

Due to the heavy focus on statistical applications and extensiveamount of time and training that was required to prepareindividuals to use these tools, a unique organizational structurewas established that allowed different titles to be used in supportof the successful deployment at GE. It created an innovativerecognition system called Black Belt Program to support its SixSigma Quality Program. Individuals progressed through variousexpertise levels as follows:

Blue Belts: Individuals who are trained in basic problem solvingand team tools, thereby establishing a common improvementapproach throughout the organization. All employees should be ata minimum at the Blue Belt level.

Yellow Belts: Individuals who have been trained to perform asmembers of Six Sigma Teams. They are used to collect data,participate in problem solving, and assist in the implementation ofthe individual improvement activities.

(Note: The Yellow Belt level was added on later to account forthose who would become members of the Six Sigma Teams andassist with the process mapping, data gathering, brainstorming,communications, and implementation of solutions.)

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Green Belts: Individuals who have completed Six Sigma training,are capable of serving on Six Sigma project teams, and managingsimple Six Sigma projects.

Black Belts: Individuals who have had advanced training withspecific emphasis on statistical applications and problem-solvingapproaches. These individuals are highly competent to serve ason-site consultants and trainers for application of Six Sigmamethodologies.

Master Black Belts: Individuals who have had extensiveexperience in applying Six Sigma and who have mastered the SixSigma methodology. In addition, these individuals should becapable of teaching the Six Sigma methodology to all levels ofpersonnel and to deal with executive management in coachingthem on culture change within the organization.

These definitions have changed over time. It’s now accepted thatGreen Belt training is different and less complex than Black Belttraining. The same levels of expertise are used to distinguishbackground levels for LSS methodologies. Although the basictheory behind Six Sigma involved everyone in the organization, inmany organizations that was not the case. In these organizationsthe Six Sigma initiative was made up of a few highly trainedGreen Belts or Black Belts whose total objective was to solveproblems that would result in large savings to the organization. Inmany cases the Black Belts were expected to save theorganization a minimum of $1 million a year or they would bereassigned. In these cases big improvement opportunities were

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acted upon and solved within 2 to 3 years and there was no needfor the Black Belts’ service anymore. As these major problemswere solved, many executives began to realize that everyoneneeded to focus on the elimination of waste, not just in theproduction areas, but also in the support areas. This has resultedin LSSGB and LSSBB becoming facilitators of waste reduction aswell as problem solvers. It also focuses the organization on wastereduction versus reducing variation. (Note: LSS does not ignoremeasurement where it is required, but does not rely upon itabsolutely as Six Sigma does.)

Lean Six Sigma Master Black Belt (LSSMBB)

The standard practice is one Lean Six Sigma Master Black Belt(LSSMBB) for every 15 to 20 Lean Six Sigma Black Belts (LSSBBs)or one for the total organization, if the organization is less than200 employees. The LSSMBB is a highly skilled project manager,

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who should be Project Management Institute certified. LSSMBBsare the heart of the organization’s LSS process. They must bemore skilled and experienced than regular LSSBBs. They shouldbe experienced teachers and mentors who have mastered theLSS tools.

The LSSMBB is responsible for:

Certifying LSSBB and Lean Six Sigma Green Belts (LSSGBs)Training LSSBBs and LSSGBs

Developing new approachesCommunicating best practices

Taking action on projects that the LSSBB is having problems indefining the root causes and implementing the change

Conducting long-term LSS projectsIdentifying LSS opportunities

Reviewing and approving LSSBB and LSSGB project justificationsand project plans

Working with the executive team to establish new behavioralpatterns that reflect a Lean culture throughout the organizationTypically, an LSSMBB will interface with 15 to 20 LSSBBs toprovide mentoring and development service in support of theirproblem-solving knowledge. When most organizations start anLSS process, they don’t have people who are experienced enoughto take on the role of an LSSMBB even when they have completedthe LSSBB and LSSMBB training.

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