Preface

The purpose of this book is to show how, using the principles of Visual Six Sigma, you can exploit data to make better decisions more quickly and easily than you would otherwise. We emphasize that your company does not need to have a Six Sigma initiative for this book to be useful. Clearly there are many data-driven decisions that, by necessity or by design, fall outside the scope of a Six Sigma effort, and in such cases we believe that Visual Six Sigma is ideal. We seek to show that Visual Six Sigma can be used by a lone associate, as well as a team, to address data-driven questions, with or without the support of a formal initiative like Six Sigma.

To this end, we present six case studies that show Visual Six Sigma in action. These case studies address complex problems and opportunities faced by individuals and teams in a variety of application areas. Each case study was addressed using the Visual Six Sigma Roadmap, described in Chapters 2 and 3. As these case studies illustrate, Visual Six Sigma is about exploration and discovery, which means that it is not, and never could be, an entirely prescriptive framework.

As well as using the case studies to convey the Visual Six Sigma Roadmap, we also want to use them to illustrate Visual Six Sigma techniques that you can reuse in your own setting. To meet this goal, sometimes we have deliberately compromised the lean nature of the Visual Six Sigma Roadmap in order to take the opportunity to show you extra techniques that may not be strictly necessary to reach the conclusion or business decision. Striking the balance this way means that you will see a wider repertoire of techniques from which to synthesize an approach to Visual Six Sigma that works for you.

Because of its visual emphasis, Visual Six Sigma opens the doors for non-statisticians to take active roles in data-driven decision making, empowering them to leverage their contextual knowledge to pose relevant questions, get good answers, and make sound decisions. You may find yourself working on a Six Sigma improvement project, a design project, a data mining inquiry, or a scientific study—all of which require decision making based on data. After working through this book, we hope that you will be able to make data-driven decisions in your specific situation quickly, easily, and with great assurance.

How This Book Is Organized

This book is organized in two parts. Part I contains an introductory chapter that presents the three Visual Six Sigma strategies, a chapter on Visual Six Sigma, and a chapter introducing JMP statistical software (from SAS® Institute), which will be used throughout the case studies.

Case studies are presented in Part II. These case studies follow challenging real-world projects from start to finish. Through these case studies, you will gain insight into how the three Visual Six Sigma strategies combine to expedite project execution in the real world. Each case study is given its own chapter, which can be read independently from the rest. A concise summary of the storyline opens each case study. Although these case studies are real, we use fictitious names for the companies and individuals to preserve confidentiality.

Within each case study, visualization methods and other statistical techniques are applied at various stages in the data analysis process in order to better understand what the data are telling us. For those not familiar with JMP, each case study also contains the relevant how-to steps so that you may follow along and see Visual Six Sigma in action.

The data sets used in the case studies are available at http://support.sas.com/visualsixsigma. Here you can also find the exhibits shown in the case studies, allowing you to see screen captures in color. Additional Visual Six Sigma resource materials will be made available on the Web site, as appropriate.

We have used different fonts to help identify the names of data tables, of columns in data tables, and commands. Data table names are shown in bold Times New Roman, while the names of columns (which are variable names) are shown in Helvetica. The names of commands are shown in bold Helvetica.

A Word about the Software

The ideas behind Visual Six Sigma are quite general, but active learning—in our view the only kind of learning that works—requires that you step through the case studies and examples in this book to try things out for yourself. For more information about JMP and to download a trial version of the software, visit www.jmp.com/demo.

JMP is available on Windows, Mac, and Linux platforms. The step-by-step instructions in this book assume that you are working in Windows. Mac and Linux users should refer to the JMP documentation for details on differences. This book is based on JMP version 8.0.1.