Industrial Statistics with Minitab

Part One

INTRODUCTION AND GRAPHICAL TECHNIQUES

As much as 95% of all problems within a company can be solved using the seven basic tools.

K. Ishikawa

A good way to start learning how to use statistical software is to give an overview: see what it looks like, consider the different possibilities offered, enter some data, develop an idea on how to handle it and start doing some simple analysis. This is what we do with Minitab in Chapter 1.

The remaining chapters of Part 1 are devoted to graphical techniques. One might think that this is an easy subject, but when we are faced with some data – usually in a format and a structure that are not best suited for our purposes – it is not always easy to decide upon the best graph (or graphics) to convey the desired information. To make a good, informative graphic requires patience: producing different types and different versions of the most promising ones, subject knowledge, and mastering the software to make them. The examples presented here are aimed at presenting and practising Minitab using its many graphical capabilities, while developing practice in identifying the graphic type most suited to different situations.

The graphs presented are organized into three groups: to analyze variability, to split the data into categories to compare frequencies and to show the relationship between variables.

To analyze the variability of a data set we can use:

• Histograms. This is the graph of choice for visualizing dispersion. It is very useful ...