There is an OOTB job that handles the notification purging: Purge Notifications job.
This job has been enhanced in 15.3 and provides a broader set of options compared to previous versions of PPM.
Below is the current logic of the job:
JOB PARAMETER DETAILS:
This will be multi select lookup showing the same values as being shown by 'Show' drop down lookup currently present at Organizer -> Notification tab.
In case user wants to select All the notification types, he has to select all the values in the Browse window. There is no default value for this field.
Date Range with Fixed and Relative Date:
From Created Date:
To Created Date:
If no value is provided then all the notifications of the selected type will be purged depending upon the other parameter values, if any are selected.
This lookup will provide the name of the resources. On selecting a resource name, specified type of notifications will be deleted just for this resource.
This parameter will show the Active / Inactive / Locked Resource Names.
Assignee OBS: This parameter will provide a list of all the OBSs available in the system to choose from.
For example: If user selects 'Timesheet' from 'Notification Type' and enters ITC in the Assignee OBS and executes the job then all the Timesheet notifications for all the resources that belong to ITC OBS will be deleted.