Question

How to delete workflow reporting data that appears in the out of the box Process Overview reports? 

Answer

Please note that the below methods of cleaning up the information shown in the process overview reports is used to delete completed instances.  This is often done on test/development environments where previous completed processes are not needed for an audit history.  The other method for cleaning up reporting information and data without deletion of data is to use the K2 Archive Tool.  Archving removes older data out of the K2 Database into a separate storage location.  This data can then be restored or in custom reporting for audit purposes.

The supported way to delete information that is shown in the process overview reports is to delete the historical log data at the time that the workflow is also deleted.

When using K2 Managment (or workspace), navigating to the Workflow Server, select a process, and then select versions.  Here you can select which versions of the process to delete.  Select the version(s) to delete, and check the "delete all historical (log) data for selected versions" option.  Note that a workflow version cannot be deleted if there are running instances utilizing that version.

In the case where a process version has been deleted, but the delete all historical (log) data for selected versions" option was not selected,  there is a stored procedure that can be run on the K2 Database. nServerLog].DlProcInstRemove] stored procedure can be used with the Process Set ID and Process Instance ID's of the records for deletion.  You can use the Workflow reporting smart objects to look up the process set ID and then Process Instance IDs.  In any case where database manipulation is used, please remember to always take a backup of the database before deleting anything.