# The Charts Tab

On this tab, you may specify the type of control charts you would like to view. You can select the charts based on type of parameter – whether variable or attributive. If no charts are selected and you click Save, an error message is displayed. At least one chart must be selected.

Charts available for Variable Type Parameters are:

- X Bar R chart

- X Bar S chart

- Histogram

- Pre-control chart (disabled)

- X chart

- X MR chart

- Pareto Chart

- Median Chart

If 100% Inspection option has been selected on the Sampling tab, then X Bar R Chart and X Bar S Chart cannot be selected.

Charts available for Attributive Type Parameters are:

- P chart

- nP chart

- U chart

- C chart

Depending on the Subgroup Size you have set on the Sampling tab, attributive charts can be selected. If Subgroup Size is greater than 0 then all charts are available. If Subgroup Size is 0 then only P Chart and U Chart are available. P and nP charts fall under ‘Based on Defectives’ group. U and C charts fall under ‘Based on Defects’ group. Charts can be selected under one group only.