Lean Six Sigma For Dummies, 4th Edition

Chapter 8

Presenting Your Data

IN THIS CHAPTER

Investigating variation using control charts

Introducing process capability

Looking at different ways to display data

This chapter outlines the importance of understanding and identifying variation. If you can identify what type of variation you’re seeing in your process results, you can determine whether action is needed or not, and avoid taking inappropriate action and wasting effort.

We introduce control charts in this chapter. They can be used to identify types of variation in your process and provide an effective way to display the data in order to tune into the “Voice of your Process.” We focus on the most commonly used type, the X moving R, or “individuals and moving range” control chart.

We also include some other data display tools: histograms and Pareto charts.

Delving into Different Types of Variation

Things are seldom exactly the same, even if at first glance they appear to be so. Variation is everywhere! For example, it exists in people’s heights, in the many shades of the color green, in the number of words in each sentence of this book, and in the time different people take to read it.

Variation comes in two types: ...