In the debate about whether Six Sigma is something new, the arguments for and against revolve in part, around the set of tools used to execute a Six Sigma project. Is Six Sigma a new set of tools or a new way to employ existing tools? The answer lies somewhere in the middle.

Many of the tools used for Six Sigma also have proved useful in conjunction with TQM and other process improvement methodologies. While some of the tools are new to process improvement activities, it is important to note that Six Sigma also provides a new way to use existing tools. It is the combination of tools and the way they are employed that gives Six Sigma its competitive advantage.

But Six Sigma is more than just tools and a methodology. To ensure success, the application of Six Sigma relies on the traditional scientific method to examine processes and remove undesirable causes and their effects. Significant value is derived from the sequence of observation, hypothesis, prediction and testing that began as the hallmark of scientific inquiry in the time of Aristotle. Traditionally, scientific inquiries examine the processes of nature in order to characterize cause-and-effect relationships. Six Sigma, and to a great extent the entire spectrum of engineering sciences, takes these same concepts and applies them to man-made systems in order to characterize the cause-and-effect relationships in value-creation (i.e., business) processes.

Belts Essentially Acting as Scientists

Consequently, Six Sigma Black Belts and even Green Belts who lead projects are essentially acting as scientists to the extent that they employ the same thought processes. As a result, the same qualities that make successful scientists are those that make successful Six Sigma Black Belts, people who shift between the statistics and the problem with little or no effort. They constantly digest process data, generate questions, probe traditional thought, test everything with data and analysis, and shift those results back to real world applications. As Black Belts lead projects through the Six Sigma DMAIC methodology, specific skills are required.

Define Phase

Ability to observe and characterize general, systemic issues. This is basic business acumen and is a skill that is often brought to the Six Sigma world by Champions and process owners who directly feel the pain of problems in their processes. It is the role of capable Black Belts to utilize empirical observation and deductive reasoning to narrow a general systemic problem to a more focused issue that can be adequately addressed given the limitations of time, data, and desired impact. In doing so, Black Belts must first be able to recognize any cause-and-effect relationship as a process, or at least part of a process. From this point, Black Belts will be able to understand and communicate the issue in the language of a process. They have the ability to take a high level process and understand the relationships between the sub-processes that constitute the higher level process. They then take the sub-processes and break them apart and, due to the understanding at a higher level, are less likely to optimize a sub-process at the expense of the larger process, also know as single-point optimization.

Measure Phase

Skeptical reliance on empirical data. Once a focused problem is defined, further observations are necessary in order to understand and comprehend the nature of the specific problem, i.e., extent, impact, frequency, amplitude, inherent variation. All observations should be studied knowing that no measurement technique is perfect. All interpretations are subject to the observer’s frame of reference. The use of quantitative data analysis, as opposed to qualitative interpretation, can significantly reduce the analyst’s bias.

Analyze Phase

Ability to use logic to characterize cause-and-effect relationships. Through multiple iterations of testing and experimentation, capable Belts must apply further deductive reasoning to identify specific root causes of the effects noted in the original problem. The application of a few common principles are particularly important:

• Ockham’s Razor – Given multiple competing theories to explain the same result, put a priority on the simplest to develop hypotheses for testing. In a sense, this is like saying, “Keep it simple, stupid.” This sorting process, if followed, will prevent Black Belts from devising complex solutions and using exotic techniques to solve relatively simple problems. It still contains enough rigor to avoid the classic “brainstormed solution.”
• Hanlon’s Razor – This rule says, “Never attribute to malice what can adequately be explained by incompetence.” In other words, people make mistakes, do not assume they are failing on purpose. Look for issues in the process or system that allow or encourage mistakes. More times than not people do things for a reason, i.e., lack of understanding of consequences on down-stream processes, fear, random data from a poor measurement system, etc. By understanding those reasons, skilled Black Belts become more knowledgeable of the inadequacies of the process under investigation.
• Intellectual Flexibility – Truly understanding a process requires multiple cognitive skills such as rational, analytical, intuitive, aesthetic, creative and moral, to name a few. The belief that any one is the proverbial silver bullet is “intellectual bigotry.” And just as with any other form of bigotry, it is based in ignorance.
• Passion for Knowledge – Apprehending the true nature of a process is at once intellectually, decisively and spiritually liberating. Do not infer that Six Sigma is a secret society, a society with secrets or that it is some kind of esoteric path to enlightenment. It is not. However, discovering the truth in a sea of ignorance, apathy and ambiguity should bring good Black Belts personal satisfaction, even in the absence of monetary reward or other recognition – an aesthete of an efficient process.
• Intellectual Honesty – It is important for Black Belts to recognize and admit the extent to which the “truth” remains unknown. Aberrations or unexpected results must be reported and explained without fear of personal repercussions. The consequences belong to those who fail to report and chronically cannot explain. Furthermore, successful Black Belts will constantly question the extent to which inputs simply correlate with outputs versus a quantifiable true cause-and-effect relationship.

Children see with “new eyes.” That is because they do not look through all the experiential prisms adults do. Those prisms cause adults to interpret something rather just experience it. Skilled Black Belts have learned to use data to help them return to new eyes. They use data and statistics to assist them in objectively experiencing something. Without the baggage of previous experiences, events take on a much freer meaning. The new meaning is what they use to create new questions. Just as a child can endlessly ask why, Black Belts use statistics to analyze a set of data, draw a conclusion and formulate the next question. These questions are the compass that skillful Black Belts use to identify the trail of clues that lead them to the new solution. By exhibiting these characteristics, capable Black Belts are able to arrive at the vital few root causes of undesirable effects in their processes by way of an efficiently designed and executed Analyze phase.

Improve Phase

Inductive reasoning. With all the available information derived from their analyses, Black Belts must be able to effectively apply the knowledge gained from specific (often narrow) frames of reference to the broader context of their processes. Truly talented Black Belts are multi-lingual in that they speak the language of the process and the language of statistics. As any multi-linguist knows, it is hopeless to try to impress an audience which does not speak the language. That is particularly true when the language is statistics. Successful Black Belts move easily and fluidly back and forth between the two – statistics and the process. In this way, Black Belts can fuel the creative process for deriving solutions in a successful Improve phase.

Control Phase

Action and initiative. Much has been written about the intellectual characteristics required to be a successful Black Belt, but none of this is meaningful if Belts are not willing to perform the work necessary to make change happen. Execution, the book by Larry Bossidy, chairman and former CEO of Honeywell International, is entirely dedicated to the critical importance of implementation and institutionalization even beyond the purview of Six Sigma. A Six Sigma project that does not deliver becomes a waste of resources thereby increasing the cost of poor quality (COPQ) rather than increasing the efficiency of the process.

Scientific Thinking at Heart of Six Sigma Success

While Six Sigma teaches and relies upon the use of specific tools to execute the problem-solving process, the basic tendency towards critical, scientific thinking lies at the heart of its success. No set of tools, whether they are team facilitation methods, change management techniques or statistical/analytical applications, can substitute for basic cognitive characteristics. Consequently, Six Sigma is not just a toolbox. It is a way of thinking about the business, about processes, and about cause-and-effect relationships.

So if Six Sigma is not about the tools, why are tools such an important part of the curriculum? The answer to that is that use of the tools helps to develop the sense of critical thinking and scientific perspective necessary for successful problem-solving. Statistics, more than simply a branch of mathematics, is a way of viewing an environment.

This truth also speaks to the issue that, while specific tools are taught for application during specific phases of the Six Sigma sequence, an accomplished Black Belt will employ various tools at any phase, regardless of whether the traditional deliverables of a phase require use of such tools.

Though it may be different, refreshing, even liberating, Six Sigma is not entirely new. It seeks to innovate through the discovery of truth with refined, rational cognitive skills and the objective analysis of empirical data. It is a collection of tools. It is a methodology. It is a thought process that dissects the large picture into smaller parts and reassembles it into a more efficient configuration. And most of all, Six Sigma delivers uncommon results.