A Summary of Six Sigma for Managers, by Greg Brue

Six Sigma for Managers, by Greg Brue, provides its readers with a thorough understanding of the basic principles of Six Sigma and its implementation. To Brue, Six Sigma means many things for an organization. First, Six Sigma is a statistical basis for measurement, allowing the organization to quantify how well they are producing quality material by measuring the Defects Per Million Opportunities (DPMO). Second, it provides a philosophy and a goal for the organization to get behind, and be motivated by. Third, it provides a methodology through a five-step process, also known as the five “vital factors.” And finally, it provides a symbol of quality for the organization, and a sense of pride when the organization achieves its goal.

This summary will focus on these four concepts, listed above.

Six Sigma for Managers
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Brue describes Six Sigma as a journey – “a journey for business professionals who are truly committed to improving productivity and profitability.” He then makes the argument that with Six Sigma, one can “eliminate most errors, reduce [one’s] costs, and better satisfy [one’s] customers.” To do this, it’s important to understand how Six Sigma originated. Brue suggests that it originated after World War II with W. Edwards Demming and his Total Quality Management (TQM) philosophy. During this time period business underwent a paradigm shift, or a stage of “unlearning,” and by the mid-1980’s the number of businesses focusing on quality management was significant. From this paradigm shift arose the Six Sigma methodology. It provided many things for an organization, as described above. The first of these is a statistical basis for measurement.

Statistical Basis for Measurement

When describing the statistics involved in Six Sigma implementation, it is important to understand the standard deviation and variance for each process. With these measurements, along with other basic statistical and graphical tools, one can develop metrics to help understand how the processes in the organization are functioning. One key measurement, as noted by the name Six Sigma, is that of defects per million opportunities (DPMO). When an organization achieves Six Sigma, their DPMO is at or below 3.4 DPMOs, or an error ratio of 3.4:1,000,000. The reasoning behind this is that, under the normal curve, six standard deviations from the mean accounts for 99.9997% of all instances. In other words, if the process is performed without error for six standard deviations, that leaves an error percentile of 00.00034% — or 3.4 DPMO.

Normal curve demonstrating the concept of Six Sigma

Brue also describes that Six Sigma is based on a few key concepts. These concepts are defects, variations, critical-to-quality (CTQ) metrics, process capability indices, and designs. Another important metric, in my mind, is the cost-of-poor-quality (COPQ) metric.  These metrics should be used as baselines for judging how well the organization is implementing Six Sigma methodologies. By setting baselines and benchmarks, the management can then conduct a Gap Analysis to see how the organization is progressing.


Secondly, by providing a philosophy and a goal for the organization, it makes the program easier to implement. Brue outlines many do’s and don’ts to a Six Sigma project in chapter four. Many of these focus on empowering employees to improve, and planning for the future. One of the common themes in this chapter is the concept of prevention, and how important it is to take measures to prevent errors from occurring. Empowering employees to assess and correct opportunities for errors, in my opinion, is the smartest and most effective way to implement this program. Also, Brue outlines the importance education and communication in the organization. Once everyone is on the same page with the Six Sigma plan, it is important to then open lines of communication – to enable people to work through problems with a focus on prevention.

Methodology — Five Vital Factors

Next, Brue outlines what he likes to call the core of Six Sigma – or the “vital factors.” These factors form the acronym DMAIC, or: Define, Measure, Analyze, Improve, and Control. These factors provide a sequential method for solving problems in an organization.

The first two steps involve gathering information that is relevant to the problem. By defining what the problem is, it is much easier to determine what information is needed. Once the problem is defined, one must then measure the variables of interest using metrics, as discussed previously.

The third step involves an analysis of these metrics. By using the metrics to determine where the root of the problem lies, one can then take corrective action to prevent that error from occurring.

The fourth and fifth steps involve acting upon one’s analysis of the problem. By improving the problem, one must come up with a solution that can help eliminate the error, and then implement that solution. Finally, once that solution has been implemented, one must control the process to ensure the process is running within the pre-determined control limits. This control process is the crucial last step. If the process cannot be controlled, the procedure should be repeated to determine what else might be causing the error.

A graphic of the DMAIC process

Symbol of Quality & Organizational Pride

Finally, since Six Sigma is a well-known quality management tool, and it provides measurable results, it can prove to be a symbol of quality within the organization. Since business usually perform between three and four sigma, if a business can achieve Six Sigma, upper management can use it as a sales tool, a motivational tool, or even a reputation tool. However, not only can upper management use the Six Sigma status to their benefit. Employees can use it as a career builder and become more active and involved in the process, creating a second-generation of upper management candidates.

By implementing a Six Sigma project in one’s organization, one can improve productivity and profitability, while also improving the quality of one’s products and increasing customer satisfaction.

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