X Bar Chart Monitors. An X-Bar and R-Chart are control charts utilized with processes that have subgroup sizes of 2 or more. From the drop-down list select All observations for a chart are in one column and enter Machine 1 Machine 2 Machine 3.
The control limits for the Xbar chart are given below. The control limits on both chats are used to monitor the mean and variation of the process going forward. Because the production volume is steady and the standard deviation is expected to be consistent across all cracking pressure settings a target Xbar-R chart is used to monitor the process.
The X with the two lines above X double bar is the overall average.
Use Xbar Chart to monitor the mean of your process when you have continuous data in subgroups. Open the sample data CamshaftLengthMTW. X-bar and R charts are used to monitor the mean and variation of a process based on samples taken from the process at given times hours shifts days weeks months etc. Use this control chart to monitor process stability over time so that you can identify and correct instabilities in a process.
