Stephen R. Covey

You don’t have to wait until your multi-vari data are collected to start creating the multi-vari chart for Six Sigma. Instead, you can build the chart, incrementally, adding more to it as you collect more data.Multi-vari charts can be drawn by hand; in fact, the process operators themselves can create them, providing those folks with a critical opportunity to invest themselves in the discovery of the root cause and the development of the solution.

To apply Six Sigma to your business and produce the best results, you need to understand what Six Sigma is, the principles of Six Sigma, and the DMAIC problem-solving method. The correct tools and use of the Six Sigma scale and methods will keep your data dependable and reusable.What is Six Sigma?Generally, Six Sigma is a set of techniques and tools that help businesses improve their processes.

In Six Sigma, you make progress the old-fashioned way — one project at a time. In essence, projects are the unit of change; they define the collective effort by which most Six Sigma progress is accomplished. Projects represent — and in fact are — the level of granularity expressed to manage Six Sigma change, from a single process improvement to a large-scale business improvement effort.

A cause-and-effect matrix — sometimes called a C&E matrix for short — helps you discover which factors affect the outcomes of your Six Sigma initiative. It provides a way of mapping out how value is transmitted from the input factors of your system (the Xs) to the process or product outputs (the Ys). With these relationships visible and quantified, you can readily discover the most-influential factors contributing to value.

The DMAIC (Define-Measure-Analyze-Improve-Control) project method is a formalized problem-solving process of Six Sigma. It’s made-up of five steps to apply to any procedure of a business to improve effectiveness. Define: Set the context and objectives for your improvement project. Measure: Determine the baseline performance and capability of the process or system you’re improving.

Six Sigma is based on a handful of basic principles, and these principles create the entire Six Sigma arrangement. Here are Six Sigma’s fundamental principles: Y=f(X) + ε: All outcomes and results (theY) are determined by inputs (theXs) with some degree of uncertainty (å). To change or improve results (the Y), you have to focus on the inputs (theXs), modify them, and control them.

After you’ve homed in on the problem area, you need to define the business case for the Six Sigma project approach you’re considering. Writing the business case helps you describe or characterize the issues and estimate the potential value of improvement projects. At this stage, you aren’t looking to define the project but rather to identify the value.

Having the right tools and knowing how to apply them to your Six Sigma projects will help you produce accurate, acceptable, and reusable outcomes. Here’s an overview of the Six Sigma landscape:

The Six Sigma scale shows how well a vital feature performs compared to its requirements. The higher the sigma score, the more efficient the feature is. This table shows the universal Six Sigma scale: Sigma Level (Z) Defects per Million Opportunities (DPMO) Percent Defects (%) Percent Success (Yield %) Capability (CP) 1 691,462 69 31 0.