# Verifying build

After a successful system build the System Summary is prepared to document the data load.

The **System Summary** tree is navigated by opening and closing variables and folders by clicking on the ‘+’ icon. The right panel displays results relevant to the FastStats object highlighted in the tree.

**FastStats System** displays overall load totals.

Table summaries show the numbers of records read and minimum and maximum matches for join relationships.

Selector variable summaries have a comprehensive display of frequency counts for all valid codes and invalid codes detected. Valid codes are those that are defined in the [Decodes](<https://help.apteco.com/en/designer/define-variables/selector-decodes/index.md>).

Numeric variables display the range of values detected, statistics and missing value counts.

## Summary menu

From the menu you can choose to refresh the system summary or to save the system summary as a .HTML report.

Check the Build Performance tab to get a breakdown of how long each build stage took for each table: