X Bar R charts are the widely used control charts for variable data. They help to examine the process stability in many industries.
An XmR chart (aka Shewhart’s Control Chart aka ImR chart) is a chart where the control limits are calculated from the moving average range.
Control charts are a great tool to help determine if a process is under statistical control, the level and source of variation experienced.
A product may have many defects – imperfections. But a product is not defective unless the defects prevent the product from functioning.
Six Sigma documentation refers to documents that contain details about the project. It is a tool to gather facts & thoughts in a formal way.