The WindchillSystemCustomizationsReport.xml report gathers details of cutomizations made to your Windchill system. You can use this report to determine the modifications made to your Windchill system, such as class files or property files, as part of the customizations. A visibility into the customizations is especially useful when migrating or upgrading your Windchill systems. You can set the frequency of report generation to every two weeks or every month.