The immediate origin of Six Sigma can be traced to its early root at Motorola, and specifically to Bill Smith (1929 - 1993). Mr. Smith was born in Brooklyn, New York in the Winter of 1929 at the start of the Great Depression. Little else has been written about Bill Smith beyond the fact that he graduated from US Navy Academy in 1952 and studied t the University of Minnesota School of Business. Bill Smith was an employee of Motorola and a Vice President and Quality Manager of Land based Mobile Product Sector, when he approached Chairman and CEO Bob Gavin in 1986 with his theory of latent defect. The core of the theory is that variation in manufacturing processes is the main culprit for defects, and that if variation can be eliminated, defects will too and that the company will make lots of money. The threshold determined by Smith and agreed to by Motorola is 3.4 defects per million opportunities (3.4 DPMO) which is derived from sigma shifts from specifications. Motorola went on to win the first ever Malcolm Baldrige Excellence Award in 1988, just two years after Bill Smith’s introduction of Six Sigma - And this award has been credited with fueling the popularity and widespread adoption of Six Sigma beyond its early roots as a process control methodology into an organization improvement philosophy and the leading inheritor or usurper (depending on what side of the argument you choose) of Total Quality Management (TQM).
The tools and techniques used by Bill Smith where by no means new when he developed them into a coherent strategy for improving Motorola production processes. Indeed, the concept of Statistical Process Control has been attributed to Walter Shewhart (1891 - 1967) and his Student, Edwards Deming (1900 - 1993).
Walter Andrew Shewhart was a physicist, engineer and statistician often referred to as the father of statistical process control. A native of New Canton Illinois, Shewhart attended the University of Illinois and got his PhD in Physics from University of California Berkeley in 1917. When Walter Shewhart joined the Western Electric Company
inspection of engineering department in 1918, industry quality control was mostly limited to inspecting finished products and removing defective items (similar to how many organizations still do quality control today). The problem was that in the early part of the twentieth century, Bell Telephone engineers were trying to improve telephone transmission reliability, but because amplifiers and other equipment used for transmission were buried underground, making changes after installation was quite expensive, and there was a growing need to minimize incidents and rates of failures and repairs or defective components. Dr. Shewhart was reputed to have approached his boss, George D. Edwards with a prepared memorandum, about a page long, the highlight of which was arguably the first schematic of a control chart and short explanatory text. Shewhart identified variation as the principal culprit for defects in the device manufacturing process and he pointed out that reducing variation, and keeping the process in control will improve quality - he surmised that continual process-adjustment in reaction to non-conformance actually increased variation and degrade quality.
Dr. Shewhart suggested there are two key causes of variation; assignable-cause(or special-cause variation), and chance-cause (or common-cause variation). He introduced the control chart to distinguish between the two, stressing that bringing a production process into a state of statistical control, where there is only chance-cause variation, and keeping the chance-cause variation in control, is it possible to predict and manage a process cost effectively or economically.
Assignable Cause variation is unanticipated, emergent or previously unknown or unanticipated phenomena within the system. This type of variation is inherently unpredictable (even probabilistically), and can be outside of the historical experiential base. It is usually characterized as a signal within the system itself and often a surprise to practitioners or workers in the process. Examples of special cause variation include operator failure (for example an operator falling asleep on the job), faulty controllers (example include software failure), machine malfunction, computer crashes, power surge, abnormal web traffic (sudden, unexpected surge in clicks), absent operators or some other unexpected (and unplanned) system breakdown.
Chance Cause variation are well known, expected part of the system with predictable variations. Variation may be irregular, but is within an historical experiential base and may also lack significance in individual high or low values. In a way, common cause variation can also be described as the inherent system noise. Examples of chance cause variation include inappropriate procedures, poor designs, poor maintenance, lack of clearly defined procedures, poor working conditions, substandard raw materials, inadequately trained personnels, quality control errors, incomplete testing, vibrations in industrial or manufacturing process, normal system wear and tear, computer response time etc.
Despite his intellectual heft and the clear value of his work to Bell Telecommunication and other organizations, Shewhart best contribution may have been his mentee and student, Edward Deming. William Edward Deming was born in the Falls of 1900, earned his BSc in electrical engineering from University of Wyoming at Laramie in 1921, a Master of Science degree from the University of Colorado in 1925 and later a PhD from Yale in 1928. His graduate degrees where in Mathematics and Physics. Deming had an internship at Bell Telephone Laboratories in the late 1920s while studying at Yale where he also met Dr. Walter Shewhart. He worked at the US Department of Agriculture, and later the Census Department. Post World War 2, he worked as a consultant to the Japanese government, under Gen. Douglas MacArthur as a census consultant. While in Japan. Deming made a significant contribution to Japan’s reputation for innovative high-quality products, and later Japanese economic power, and is highly regarded as the single non Japanese with most impact on that nation’s manufacturing and business outcomes and growth during and post Marshal plan.
Deming studies electrical engineering between 1917 and 21 at the University of Wyoming at Laramie and obtained graduate degrees in Physics and Mathematics from University of Colorado (M.S. - 1925), and Yale University (Ph.D. - 1928). In 1936, he also studied under Sir Ronald Aylmer Fisher and Jerzy Neyman at the University College, London England. Deming interned at Bell Telephone and was introduced to Dr. Walter A. Shewhart by Dr. C.H. Kunsman of the USDA in 1927. Deming found great inspiration in Shewhart’s work on statistical process control and the control chart and as he took more interest in the application of statistical process control to industrial production and management, he realized that Shewhart’s ideas could also be applied to the processes by which enterprises are led and managed. In 1939, he edited a series of lectures delivered by Dr. Shewhart at USDA into a book, Statistical Method from the Viewpoint of Quality Control. His uncanny ability to distill Shewhart’s work into more accessible form helped popularized those ideas and their application later in the century account for his great influence on the economics of the industrialized world, post second world war. One of Deming’s key philosophical view point can be characterized by the following equation:
- When people and organizations focus primarily on quality as defined by
- Quality = (Results of work efforts)/(Total costs)
- quality tends to increase and costs fall over time
- When people and organizations focus primarily on costs, costs tend to rise and quality decline over time.
Deming’s contributions to quality control earned him the title of the Father of Modern quality management and his work was foundation to much of Total Quality Management. He developed the concept of System of Profound Knowledge, also known as Deming System of Profound Knowledge where he advocated that all managers need to have the following key knowledge :
- Appreciation of a system - An understanding of the overall system which includes suppliers, producers, customers (or recipients) of goods and services.
- Knowledge of variation - The range and cause(s) of variation in quality, and the use of statistical sampling in measurements.
- Theory of Knowledge - The concepts that explains knowledge and what can be known.
- Knowledge of psychology - The concept of human nature.
These ideas are fundamental to Total Quality Management (TQM). TQM is defined by the American Society for Quality (ASQ) as a management approach to long term success through customer satisfaction. ASQ is for the most part the guardian of TQM and has developed a set of certifications built around a body of knowledge to which Deming’s set of management practices described in his book, Out of a Crises :
- Create constancy of purpose (Corporate Vision and Mission) for improving products and services
- Adopt the philosophy of improvement (or TQM)
- Cease dependence on inspection (or assessments) to achieve quality.
- Stop awarding contracts (or businesses) based on price alone - emphasis total cost of ownership and added value.
- Continuously improve every planning, production, and service process.
- Institute on the job training (as a part of continuous improvement)
- Institute leadership - focusing on helping people and machines do a better job.
- Eliminate fear, so that employees work more effectively for the enterprise.
- Eliminate organizational silos, helping employees see the global view of the organization and better appreciate their role in the overall output of the enterprise.
- Eliminate slogans, exhortations and targets for the workforce - The assumption being that the bulk of the cause of low quality and low productivity is the system (or processes) and often are beyond the power of the workforce.
- Eliminate numerical quotas for workforce and numerical goals for management - instead substitute leadership for quotas.
- Remove barriers that rob the hourly worker of his/her rights to pride of workmanship and or eliminate the annual merit system.
- Institute a vigorous program of education and self-improvement for everyone in the enterprise.
- Engage everyone in the enterprise in the task of organization transformation.
The journey to process quality is a long one, and the pace has accelerated since the days of Henry Ford’s Just-In-Time (JIT) production system where the emphasis was on cost control, rather than defect reduction; to Edward Deming’s TQM which focused on elements of statistical process control as well as organization transformation, to Toyota Production System (TPS) which emphasizes, elimination of waste and continuous rapid improvement (using many tools similar to those used in Lean Enterprise) and to Six Sigma at Motorola.
While Six Sigma continues its evolution as a methodology and a philosophy, its increasing popularity and increasing widespread adoption continues to fuel debates about its value, and even about concepts like standardization, certification as well as the role of the core metric - 3.4 DPMO.
The term Six Sigma was coined by Bill Smith in 1986, while at Motorola, it was coined as a target for defect free product manufacturing. The term was derived from the idea that process capability can be described by product or service deviation from specification. For example, if a widget specification is diameter of between 0.01mm and 0.015 mm and for every ten million widgets, 34 are outside the specification, then the process capability sigma level is said to be 3.4 defects per million opportunities or in sigma term six sigma. It is important at this point to note that there is some mathematical magic in these numbers. Indeed, a process
References
- Walter A. Shewhart : http://en.wikipedia.org/wiki/Walter_Shewhart
- William Edwards Deming: http://en.wikipedia.org/wiki/W._Edwards_Deming
- Mikel J. Harry : http://www.mikeljharry.com/milestones.phphttp://www.pqa.net/ProdServices/sixsigma/W06002009.html
- List of Six Sigma Companies : http://en.wikipedia.org/wiki/List_of_Six_Sigma_companies
- Six Sigma: http://en.wikipedia.org/wiki/Six_Sigma
- Control Chart: http://en.wikipedia.org/wiki/Control_chart
- Toyota Production System: http://www2.toyota.co.jp/en/vision/production_system/
- Seven Basic Tools of Quality : http://en.wikipedia.org/wiki/Seven_Basic_Tools_of_Quality
- Plan Do Check Act : http://en.wikipedia.org/wiki/PDCA
- Engineering Statistics Handbook, National Institute of Standards and Technology (NIST) - http://www.itl.nist.gov/div898/handbook/
Some Six Sigma companies
3M
Acme Markets
Advanced Micro Devices
Agilent Technologies
Air Canada
ALCAN
Amazon.com
AXA
BAE Systems
Bank of America
BD Medical
Bechtel Corporation
Boeing
Cabot Microelectronics Ltd
CAE Inc
Canada Post
Caterpillar Inc.
Chartered Quality Institute
CIGNA
Cintas Uniforms
Cognizant Technology Solutions
Computer Sciences Corporation
Cookson Group
Corning
CoorsTek
Cummins Inc.
Deere & Company
Dell
Delphi Corporation
Denso
DHL
Deutsche Telekom
Dominion Resources
Dow Chemical Company
DSB Bank
DuPont
Eastman Kodak Company
EMC
Finning
Flextronics
Ford Motor Company
General Electric
General Dynamics
Genpact
GlaxoSmithKline
HCL Technologies
Heinz Co.
Honeywell
Hertel
HSBC Group
Idearc Media
Ingram Micro
Inventec
ITC Welcomgroup Hotels, Palaces and Resorts
ITT Corporation
JEA
Korea Telecom
KTF
LG Group
Lockheed Martin
Mando Corporation
Maple Leaf Foods
McKesson Corporation
Merrill Lynch
Microflex Inc.
Motorola
Mumbai's dabbawalas
Network Rail
NewPage Corporation
Nielsen Company
Nortel Networks
Northrop Grumman
Owens-Illinois
Pakistan International Airlines
Pakistan State Oil
Patheon
Penske Truck Leasing
PepsiCo
Precision Castparts Corp.
Quest Diagnostics
Raytheon
ResMed
Samsung Group
Sears
SGL Group
Shinhan Bank
Shinhan Card
Shop Direct Group
Siemens AG
SKF
Starwood Hotels & Resorts Worldwide
Staples Inc.
Sterlite Optical Technologies
Target Corporation
Teradyne
Trane
Textron
The Hertz Corporation
The McGraw-Hill Companies
The Vanguard Group
TomoTherapy, Inc.
TRW
TSYS (Total System Services)
Tyco International
Unipart
United States Air Force
United States Army
United States Marine Corps
United States Navy
UnitedHealth Group
Vodafone
Volt Information Sciences
Whirlpool
Wipro
Xchanging
Xerox
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