Six Sigma 101


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Six Sigma 101

  1. 1. Six Sigma 101 This defect-measurement and quality-improvement tool was designed to make businesses as successful as possible. Its ultimate objective: Deliver worldclass performance, reliability and value to the customer. BY SUBRAMANIAM MANIVANNAN ix Sigma is a metric for measuring America’s most gifted CEOs, such as goal in mind: make their businesses as S defects and improving quality, and a methodology to reduce defect lev- els below 3.4 defects per million oppor- Motorola’s Bob Galvin, Allied Signal’s Larry Bossidy and General Electric’s Jack Welch. These people had a single successful as possible. Once they were convinced that tools and techniques of Six Sigma could help them do this, they tunities (DPMO). It provides a method to manage process variations that cause Total Quality Management versus Six Sigma defects—defined as unacceptable devi- ation from the mean or target—and Total Quality Management Six Sigma systematically work toward managing An infrastructure of dedicated change agents focusing A functional specialty within on cross-functional value-delivery streams rather than variation to eliminate those defects. the organization functional division of labor The ultimate objective of Six Sigma is to Focuses on strategic goals and applies them to cost, deliver worldclass performance, relia- Focuses on quality schedule and other key business metrics bility and value to the end customer. Driven by tangible benefit for a major stockholder Motivated by quality idealism Advantages over TQM group (customers, shareholders and employees) In some aspects, total quality man- Loosely monitors progress Ensures that the investment produces the agement (TQM) and Six Sigma share toward goals expected return the same philosophy of how to assist organizations in improving quality. People are engaged in routine duties Slack resources are created to change key business (planning, improvement and control) processes and the organization itself They both emphasize the importance of top-management support and leader- Emphasizes problem solving Emphasizes breakthrough rates of improvement ship. And both approaches make clear Focuses on standard performance, Focuses on world-class performance, that continuous quality improvement is e.g. ISO 9000 e.g. 3.4-ppm error rate critical to long-term business success. However, why has the popularity of Quality is a permanent full-time job Six Sigma job is temporary, and career path TQM waned while Six Sigma’s popu- with a career path in the quality leads elsewhere profession larity continues to grow? Unlike TQM, Six Sigma was not devel- Provides a vast set of tools and Provides a selected subset of tools and techniques oped by technicians who only dabbled techniques with no clear-cut and a clearly defined framework for using them to framework for using them effectively achieve results in management and, therefore, pro- duced only broad guidelines for man- Goals are developed by the quality Goals flow down from customers and senior agement to follow. The Six Sigma way of department based on quality criteria and leadership’s strategic objectives; goals and metrics the assumption that what is good for are reviewed at the enterprise level to assure implementation was created by some of quality is good for the organization that local sub-optimization does not occur Subramaniam Manivannan is quality Developed by technical personnel Developed by CEOs coach/assessor-PTO quality in the man- Focuses on long-term results, Looks for a mix of short-term and long-term ufacturing process/product support depart- expected payoff is not well-defined results as dictated by business demands ment at Ford Motor Co., Dearborn, MI. 42 METALFORMING / OCTOBER 2006
  2. 2. developed a framework to make it happen. requires creativity. And the greatest According to a recent benchmarking The differences between TQM and enemy of creativity is hierarchy. report, successful Six Sigma initiatives Six Sigma are summarized in the Total Because hierarchy in a traditional firm share three characteristics: Quality Management versus Six Sigma controls all of the resources—material • Implementation teams led by sen- table. and human—an individual employee must ior executives obtain permission from someone to • Well-organized training programs How to Make use any resource. If the resources required • Ability to create a corporate culture Six Sigma Work to pursue a creative idea are controlled that values objective performance meas- Several companies have attempted to by several positions in the hierarchy, urement. implement Six Sigma, and the results the employee must get permission from Organizations attempting to imple- proved disappointing. Why? each for things to move ahead. ment Six Sigma initiatives without • Maybe they didn’t really need Six Sigma in their company or department. • Perhaps the wrong person was cho- sen as the Black Belt. • Maybe someone at the top didn’t get behind the initiative. • Perhaps key team members didn’t understand Six Sigma, and, therefore, could not implement it effectively. Company-wide understanding of the Six Sigma process is required for company-wide buy-in and, ultimately, company-wide success. In general, proj- ects are tied to business goals that can be found in the Balanced Scorecard or other system, which allows a company to make sure their efforts are directed to critical areas. Six Sigma betters an organization at all levels. At the highest level, this involves moving the entire organiza- tion from a Three or Four Sigma busi- ness process to a Six Sigma process, which requires reducing defects by a factor of more than 20,000, completely transforming the organization’s culture. What does that mean? Consider 3.8 Sigma, which reflects a process that is “99 percent good.” This may mean 20,000 lost articles of mail per hour, unsafe drinking water for almost 15 min. per day, 5000 incorrect surgical opera- tions per week and two short or long landings at most major airports each day. Six Sigma, reflecting a process that is “99.99966 percent good,” means seven lost articles of mail per hour, unsafe drinking water for 1 min. every seven months, 1.7 incorrect surgical opera- tions per week and one short or long airplane landing every five years. Quite a difference. But Six Sigma can’t be accomplished simply by tweaking the process—it 43
  3. 3. Six Sigma addressing these three areas are far less used by Black Belts and Green belts, Six Sigma’s impressive bottom-line likely to reap the rewards enjoyed by including up-to-date computer tech- results normally flow from Six Sigma successful Six Sigma programs. Key nology, are highly advanced. But the projects. drivers for Six Sigma success include tools are applied within a simple per- Properly defined Six Sigma projects winning executive support for Six Sigma formance-improvement framework meet certain criteria: initiatives, linking Six Sigma with suc- known as Define-Measure-Analyze- • Have clearly defined deliverables; cession planning, defining critical objec- Improve-Control (DMAIC). DMAIC • Are approved by management; tives for the Six Sigma program and is analogous to the older TQM model • Are not so large that they’re unman- demonstrating the impact of quality known as the Deming Cycle: Plan-Do- ageable nor so small that they’re unim- initiatives on customers. Study-Act. portant or uninteresting; DMAIC is used almost universally to • Relate directly to the organization’s Six Sigma Simplified guide Six Sigma process-improvement mission. Six Sigma’s magic doesn’t lie in sta- projects.Although truly dramatic improve- tistical or high-tech razzle-dazzle but in ment in quality requires transforming The DMAIC Process Defined tried-and-true methods that have been the management philosophy and organ- D = Define around for decades. In fact, Six Sigma ization culture, the fact is that actual Define is the first phase of the discards a great deal of the complexity projects must be undertaken sooner or DMAIC model. The purpose of the that characterizes TQM. By one expert’s later to make things happen. Projects are Define phase is to refine the project count, there are more than 400 TQM the means through which processes are team’s understanding of the problem to tools and techniques. Six Sigma takes a systematically changed—the bridge be addressed and define customer handful of these methods and trains a between the planning and the doing. expectations for the process. small cadre of inhouse technical leaders, However, DMAIC is not a method of Elements of this phase include a spe- known as a Six Sigma Black Belts or planning projects. Project planning is a cific statement of the problem being Green Belts, to a high level of profi- subject in its own right. Although proj- addressed, descriptive statements out- ciency in the application of these tech- ects and plans are closely related, they lining locations and/or occurrences of niques. To be sure, some of the methods also differ in many respects. problematic events, and an initial 44 METALFORMING / OCTOBER 2006
  4. 4. Six Sigma The DMAIC Process 80-percent target.” Then the team must clearly define and quantify the problem, identify the potential metrics and meas- urement sources, and identify the neg- ative attributes and current perform- ance, and their relationships to the customer. Questions to ask in this phase include: Who is my customer? What matters, what is critical to quality? What is the scope? What defect am I trying to reduce? By how much, what is the goal? What is the current cost of the defects? M = Measure The Measure phase establishes tech- statement describing the scope of the The team must develop a problem niques for collecting data about the problem. statement, a specific statement of the current performance and how well it is In this phase, the project team defines problem being addressed. It is extreme- meeting customer requirements. Upon what is needed for a successful Six ly important to identify the right prob- completion of this phase, the project Sigma project. Defining includes iden- lem. “Our first run is too low” is too team will have a data-collection plan, tifying customers (internal/external), general—not a good problem identifi- valid measurement system that ensures identifying customers’ needs, and deter- er. A better one: “In June, Zone A’s aver- accuracy and consistency in data col- mining the project’s scope and goals. age first run of 60 percent was below our lection, baseline frequency for defects 46 METALFORMING / OCTOBER 2006
  5. 5. Six Sigma and sufficient data for problem analysis. How Ford Benefited from Six Sigma This phase prompts the following Ford Motor Co.’s Dearborn (MI) Engine and Fuel Tank Plant produces 1200 engines daily—2.0-liter questions: for the Focus and 2.3-liter for the Ranger—and 1.2 million fuel tanks annually for a variety of What is my process? vehicles. Nearly 1000 workers ply their trade in the 2.3-million-sq.-ft. plant that stakes a claim as Which outputs most affect quality? the world’s largest single manufacturer of steel fuel tanks. Which inputs seem most to affect With management support of its consumer-driven Six Sigma program, the plant has achieved outputs? measurable results thus far in 2006. To start, all upper management underwent intensive four- week Six Sigma Black Belt training, followed by the setting of annual Six Sigma cost-saving Is my ability to measure/detect good objectives. enough? For 2006, the plant set How is my process doing today? an objective of $6 million How good could my process be if in savings for Black Belt everything were running smoothly? projects and $2.9 million for Green Belt projects. What’s the best that my process was Through June, the Black designed to do? Belt projects have achieved 61 percent of the cost- A = Analyze saving goal, with Green The Analyze phase allows the project Belt projects achieving 28 percent. One Black Belt team to target improvement opportu- project focused on nities by taking a closer look at the data. production of engine cam Through this phase, the team will deter- shafts, where two specific mine why, when and where defects plant operations were each occur; select the appropriate graphical saddled with a 17-percent scrap rate. Working with analysis tools and apply them to the suppliers and closely examining grinding operations, as well as adopting new tooling and gauging, data collected; and target a set of poten- one operation was able to cut its scrap rate to 2 percent. The other has seen its scrap rate cut to tial improvements for action in the fol- 14 percent with plant Black Belt project champions still addressing the issue. lowing Improve phase. After analyzing, 48 METALFORMING / OCTOBER 2006
  6. 6. the team can deliver a detailed process ing plan to document the changes and map, a refined problem statement and improvements. WANT estimates of opportunities for defects. Questions to ask yourself in the Con- Questions to ask in the Analyze trol phase include: MORE? phase include: Once I’ve reduced the defects, how Learn more about quality improve- Which inputs most affect quality, do the functional team and I keep them ment for metalformers by visiting and to what extent? there? If I change an input, do I really What do I set up to keep perform- and clicking on the Testing & change the output? ance satisfactory even when things Inspection/Quality Control How many observations do I need to change (people, technology and cus- Enterprise Zone. draw conclusions? tomers)? MF What level of confidence do I have regarding my conclusions? I = Improve In the Improve phase, the project team develops, implements and vali- dates improvement alternatives that will fix the process. This consists of brainstorming to generate improve- ment alternatives, testing proposed solu- tions using a pilot and validating the improvement. With this comes creation of a new process map to illustrate the new process flow followed by a cost- benefit analysis to ensure that the poten- tial improvement is viable and cost- effective. By collecting and analyzing data on the new process, the team can demonstrate validity of the improve- ments. This phase will deliver solutions to the problem and validation of those solutions as well as implementation and communication plans. Questions for the Improve phase include: Once I know for sure what inputs most affect my output, how do I imple- ment changes? How many trials do I need to run to find and confirm the best setting/pro- cedure for these key inputs? C = Control The Control phase institutionalizes process/product improvements and monitors ongoing performance in order to sustain the gains achieved in the Improve phase. During this phase the team will develop a control strategy based upon the results of the previous four phases, a control plan that incor- porates changes into the process in a timely manner, and an updated Quali- ty Performance Statement and train- 49