Six Sigma Basics - Techniques and Considerations


What is Six Sigma?

A review of the current literature on quality and process improvement frequently reflects a relatively new topic — Six Sigma. Created and pioneered in the 1980s by the Motorola organization, Six Sigma has, in recent years, spread to boardrooms, training departments, and cross-functional teams in major corporations. Although Motorola's original objective for Six Sigma was to focus on the reduction of defects in the manufacturing processes, it soon became clear that Six Sigma standards could also be applied to service organizations where the emphasis was placed on the reduction of errors made in administrative processes (document preparation), marketing and sales, distribution, and the various data base and record-keeping functions.

The author was trained and certified by Motorola in 1995 as a Master Six Sigma trainer, and he has come to appreciate the systemic approach, the logic of required activities, and the use of bundled tools that can produce the measurable results organizations often failed to achieve under the umbrella of Total Quality Management (TQM).

What is Six Sigma? The current texts describe Six Sigma in many different ways — as an improved quality assurance program, an updated measurement/improvement process, a new methodology, a philosophy, a strategy, or a quality initiative. The author believes on a strictly stand-alone basis that not one of these terms will fully describe the true power of Six Sigma. A better definition would be that of a new work ethic, a top to bottom approach of how the organization performs to meet customer expectations. Two widely recognized gurus of Six Sigma, Mikel Harry and Richard Schroeder, authored a informative book on Six Sigma titled Six Sigma: The Breakthrough Management Strategy Revolutionizing the World's Corporations (2000) in which they define Six Sigma. They see the strategy as "a business process that allows companies to drastically improve their bottom line by designing and monitoring everyday business activities in ways that minimize waste and resources while increasing customer satisfaction." In addition, Mikel Harry (2000, July) suggests three "primary vehicles for delivering breakthrough" drawn as a Venn Diagram showing three circles that overlap so that Six Sigma is centered and surrounded by MFSS (Managing for Six Sigma), DFSS (Designing for Six Sigma), and PFSS (Processing for Six Sigma). For an example Vernn Diagram and explanation, refer to tool # 213 in this book. According to Mikel Harry, Managing for Six Sigma (MFSS):

is the underlying foundation of leadership for a Six Sigma initiative regardless of its nature. It is concerned with the creation, installation, initialization and utilization of the deployment plans, reporting systems and implementation processes that support PFSS and FDSS. The ultimate goal of MFSS is simple: to attain best in class business performance by improving the operational capability of an organization at an annualized rate of approximately 78% (Six Sigma learning curve) (p.75).

The author reviewed another definition for Six Sigma by Pande, Neuman, and Cavanagh (2000) and considers this an all-encompassing statement:

[Six Sigma is] 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 (p.xi).

This truly new work ethic requires a cultural change of continuous commitment and training at all levels in the organization. This also means that resources are made available in an ongoing effort to reduce variation in every aspect of the business, e.g. product design, supplier-provided materials, internal processes, services and administrative support. As Snee and Hoerl (2003) pointed out, "The essence of Six Sigma is about breakthrough business improvement, not incremental improvements. Six Sigma projects are defined to produce major improvement (30-60% or more) in process performance in less than 4-6 months with a significant [financial] impact. Such changes greatly change how business is conducted day-to-day."

On an operational level, Six Sigma can be linked directly to the measurement and statistical reporting of variation as measured under the Gaussian Curve. For a detailed explanation, refer to tool # 119, "Normal Probability Distribution," in this book. The curve shows 4 Sigma. Sigma (σ) is a Greek alphabet letter that describes a measure of variability, or Standard Deviation. Please refer to tool # 184 for description and examples of SD calculations. Motorola determined a long time ago that this measurement under the curve required a 1.5 Sigma process mean (nominal) shift which would result in a shifted distribution to account for a long-term process drift, in either direction under the curve and its stated specification limits. Out-of-specification results, with a mean process shift, therefore would indicate:

and no more than

66,807

Defects for 3.0 Sigma (Standard Deviations)

6,210

Defects for 4.0 Sigma

233

Defects for 5.0 Sigma

3.4

Defects for 6.0 Sigma [per million opportunities

(DPMO) or parts per million (PPM)]

If the figure of 3.4 defects is converted to a percentage of yield, it would then show 99.99966%.

  • Percent yield indication with a 1.5 Sigma process shift, as follows:

  • At (3 Sigma or 3 SD, a yield of 93.32% occurs.

  • At (4 Sigma or 4 SD, a yield of 99.379% occurs

  • At (5 Sigma or 5 SD, a yield of 99.9767% occurs

  • At (6 Sigma or 6 SD, a yield of 99.99966% occurs

Six Sigma has come to represent a business culture with a strong focus on the reduction of variation in the design and process stages to minimize defects or errors. Since most organizations today are still operating at a 3 or 4 level Sigma, one can see from the figures above how many defects could reach the customer.

What is the difference between Six Sigma and TQM? Under TQM, teams attacked a specific problem or process to reduce defects or cycle time. The savings incurred were often small or could not be validated. Six Sigma tools and procedures, in comparison, are introduced early in the Design for Six Sigma (DFSS) phase and continue to be applied to Define, Measure, Analyze, Improve, and Control (DMAIC) in the processing phase. This difference results in much greater gains since virtually every department is involved. TQM programs and team problem-solving projects were linked to or managed by quality assurance professionals, whereas a Six Sigma work ethic ideally makes every employee a process improver, eventually reducing their number of "Quality inspectors" throughout the organization.

Is Six Sigma a passing fad? A number of managers are very slow indeed in accepting or following the "new Six Sigma hype." They have seen many of the previous so-called quality initiatives come and fade away. From Quality Circles to cross-functional teams, from Lean Manufacturing to TQM, many of these organizational-change efforts did not show significant returns for training, time, and resources. Moreover, they often claim that the tools themselves are not new and had been used before. Also, in today's world, the priority is still on productivity. Who has time to experiment with a new system, even when initial results show it to be superior?

Presently, Six Sigma work is performed in many organizations, regardless of size, products, or service offered. Corporate executives have read highly publicized reports on savings of billions of dollars, realized in organizations such as Motorola, General Electric, Allied Signal, et al, companies that changed to a work ethic of Six Sigma. Now they are analyzing case studies for information on training and implementation requirements. One can gauge the interest in Six Sigma by the number of books, articles, and consulting agencies that have appeared in recent years. It is true that most tools were used in many past efforts, but the clear difference now is how these tools are bundled/sequenced and rigorously applied by management and teams alike. The new edition of the Six Sigma Tool Navigator will be of great assistance for these hard-working Six Sigma teams. The author came across some interesting information supplied by G. H. Watson (1998): "ASQ American Society for Quality] has twice conducted a future study, once in 1996 and again in 1999. In both of the studies it was evident that the quality profession would shrink as the tools of quality are extended to the masses." The Six Sigma Tool Navigator will be the master tools guide to help accomplish this!




Six Sigma Tool Navigator(c) The Master Guide for Teams
Six Sigma Tool Navigator: The Master Guide for Teams
ISBN: 1563272954
EAN: 2147483647
Year: 2005
Pages: 326

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net