X Bar R charts are the widely used control charts for variable data. They help to examine the process stability in many industries.
Control charts are a great tool to help determine if a process is under statistical control, the level and source of variation experienced.
Six Sigma documentation refers to documents that contain details about the project. It is a tool to gather facts & thoughts in a formal way.
A Scatter Analysis is used when you need to compare two data sets against each other to see if there is a relationship.
Linear regression is a statistical technique to estimate the relationship between a dependent variable and an independent variable.