Visual Six Sigma: Making Data Analysis Lean

2.4. Making Detective Work Easier through Dynamic Visualization

To solve a mystery, a detective has to spot clues and patterns of behavior and then generate working hypotheses that are consistent with the evidence. This is usually done in an iterative way, by gathering more evidence and by enlarging or shifting the scope of the investigation as knowledge is developed. So it is with generating hypotheses through EDA.

We have seen that the first and sometimes only step in managing uncertainty is to identify and quantify sources of variation. Building on the old adage that "a picture is worth a thousand words," it is clear that graphical displays should play a key role here. This is especially desirable when the software allows you to interact freely with these graphical views. Thanks to the advance of technology, most Six Sigma practitioners now have capabilities on their desktops that were only the province of researchers 10 years ago, and were not even foreseen 30 years ago. Although not entirely coincidental, we are fortunate that the wide availability of this capability comes at a time when data volumes continue to escalate.

Incidentally, many of the statistical methods that fall under CDA and that today are in routine use by the Six Sigma community, were originally developed for squeezing the most out of a small volume of data, often with the use of nothing more than a calculator or a pen and paper. Increasingly, the Six Sigma practitioner is faced with a quite different challenge, ...