2 types of variation and how we distinguish between common and special cause variation, along with how to create a rational subgroup. We also cover the equations and constants for the X-bar and R ...

Control charts have two general uses in an improvement project. Undeniably, the most common application is as a tool to ...

The classic horizontal bar chart is something we’re all familiar with. For many of us, it was the first ‘chart’ we learnt in school, usually alongside Venn diagrams and line graphs. That’s because bar ...

The extent to which products meet specifications needs to be systematically monitored in a production process. Product quality will typically be defined by two quantities: deviations from stated ...

Bar charts are too frequently used to communicate data that they cannot represent well. We strongly encourage the use of more appropriate plots to display statistical samples. Bar charts are a simple ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Somer G. Anderson is CPA, doctor of ...