Six Sigma Seeks Perfection

Developed by Motorola Inc. (www.motorola.com) in the 1980s as a problem-solving, defect-reduction methodology, Six Sigma changes business cultures.

Its goal is reducing defects to 3.4 per million opportunities presented—be that on a production line or in some other endeavor. General Electric (www.ge.com) defines an opportunity as a chance for not meeting required specifications.

According to the U.S. Army Business Transformation Knowledge Center (Army BTKC, www.army.mil/ArmyBTKC/focus/cpi/tools3.htm), Six Sigma does five principal things.

It emphasizes the need to recognize opportunities and eliminate customer-defined defects. It recognizes that variation hinders ability to reliably deliver high-quality services. It requires data-driven decisions and incorporates a comprehensive set of quality tools under a framework for effective problem solving. It provides a highly prescriptive cultural infrastructure to effectively obtain sustainable results. And, when implemented correctly, it promises and delivers substantial improved operating profit.

Train black belts

In the mid 1990s, under the leadership of Jack Welch, GE embraced Six Sigma, notes Forrest W. Breyfogle III, founder and chief executive officer of Smarter Solutions Inc. (www.smartersolutions.com), an Austin, Texas, consulting firm. “As part of the GE Six Sigma system, there was practitioner and management training.” The Black Belts, highly trained practitioners, learned DMAIC, a business-improvement process or road map. It stands for define, measure, analyze, improve and control—and spells out clearly what is expected of business-improvement teams. For existing businesses, DMAIC is the central philosophy.

“Project status reports were to have road-map alignment. The primary deployment success measure was money saved,” says Breyfogle. Within the past decade or so, when Lean Manufacturing waste-reduction techniques were added to DMAIC’s roadmap, “deployments became known as Lean Six Sigma,” he adds.

In DMAIC’s define phase, users scope the project at hand and create a charter, says Breyfogle, author of the three-volume “Integrated Enterprise Excellence” series, published in 2008 by Citrus Publishing, which focuses on going beyond Lean Six Sigma. Through the scoping and development of the charter, the project team and sponsors agree on what the project is and what it should accomplish, the Army BKTC indicates.

Then, in the measure phase, an execution plan is created. That involves establishing a baseline project metric “at the 30,000-foot-level,” as Breyfogle puts it. That also means conducting, as appropriate, a value-stream analysis and/or measurement-systems analysis, he notes. Creating a flowchart to describe the existing process and its execution variations is an additional step, he adds. Also, “capture wisdom of the organization (WOTO) thoughts/risks/improvement ideas through a cause-and-effect diagram, cause-and-effect matrix and failure mode-and-effects analysis.”

In the next phase—analyze—hypothesis testing with data-visualization techniques is used to gain insight into the importance of WOTO process-improvement theories, Breyfogle explains. Techniques could include regression analysis, analysis of means, variance components, multi-variable charts and marginal plots.

In the improve phase, which follows, appropriate design-of-experiment techniques are used for process-improvement-opportunity identification, he states. If Lean Six Sigma is being employed, then Breyfogle indicates use of a Kaizen event, 5S, Poka-yoke and plan-do-check-act. Also, end-users may structurally create/implement innovative ideas and statistically describe project metric improvements.

Finally, in the control phase, participants consider pre-control charts and create a control plan, Breyfogle notes. And in this final phase, the team transfers process-enhancement ownership to the process owner.

Some things obstruct pursuit of Six Sigma perfection, though. One major Lean Six Sigma deployment problem Breyfogle notes is sustainability, which occurs because “the system typically becomes a hunt-for-project-to-execute environment; e.g., find a workshop project for a trainee.” And even though the DMAIC project road map can be beneficial, the push-for-project-creation system created in that environment often leads to silo-organizational projects that don’t benefit the business, he cautions. “Projects can be answering the wrong questions relative to a targeted effort for increasing total revenue and profitability.”

C. Kenna Amos, ckamosjr@earthlink.net, is an Automation World Contributing Editor.
More in Control