Control chart analysis

Control charts are used to understand the amount of variation in a process based on the past performance of the same process. If nothing changes in a process, then past performance should be a good indicator of future performance. Control charts use this logic to help you determine how much variation you should expect from a process. If something different, unusual, or unexpected happens in the process, the control chart highlights it so that you can research the cause.

In addition, control chart analysis might yield information about the consistency of the product characteristic being measured. It might reveal that the process is unstable or producing an unacceptable level of variation. In these cases, action is needed to improve the performance of the process.