If the level of detail provided in the
ReportServerService log file is insufficient for your needs, you can take tracing to the next level by downloading the SCRUBS project (from scrubs.codeplex.com), which includes a T-SQL user database creation script, SQL Server Integration Services (SSIS) package, and a set of reports.
The SSIS package extracts execution data captured in
ReportServer.dbo.ExecutionLogStorage to a new user database. To monitor execution, you can periodically run the package. Then you can use the provided reports to discover which reports your users most commonly run, which take the most time or are the biggest, or how many of them have succeeded or failed.
SSRS 2012 also includes three related views in the ReportServer ...