Craig Gygi

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.

It’s important for your Six Sigma initiative to know if your measurement system is effective. You need solid data to initiate your project and having a solid measurement system is key. A computer disk drive manufacturer in the mid-1980s was experiencing a nagging problem with poor yields. The principle concern was that the sensitive magnetic medium coating the disks was in some way defective.

FMEA can be very valuable for identifying failure modes in a Six Sigma Initiative. After scoring the severity of the possible effects, your cross-functional FMEA team brainstorms potential causes of the identified failure mode. Think of causes for the failure mode, not for the effect. In the pizza example, you need to think of causes for why the phone is answered on or after the fifth ring, not causes for why a customer hangs up or why a customer becomes disgruntled.

Failure mode effects analysis (FMEA) is a tool you can use in Six Sigma to quantify and prioritize risk within a process, product, or system and then track actions to mitigate that risk. It’s valuable as a method for identifying and prioritizing which critical few factors you must address to improve the process in your DMAIC project.

What should Six Sigma practitioners do with all the situations where more than one X influences a Y? You use multiple linear regression. After all, that kind of situation is more common than a single influencing variable is. When you work to create an equation that includes more than one variable — such as Y = f(X1, X2, .

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: