When looking to add the Stored Process Alert Process (useful to see whether processes run in the BACKGROUND were completed successfully) the specific portlet type is not on the list.
No worries, it's actually a personal portlet that is defined to present only YOUR stored process execution results. Therefore to locate it, you need to move from the 'Create' tab in the above screen to the 'Search' tab. Searching on the keyword 'Alerts' will return the Stored Process Alert Portlet. Just add this to see your BACKGROUND stored process result status.