Drill down on the 239 tickets outside of the SLA.
Now review the detail to determine why these tickets are out of SLA. You can sort all headings to get see patterns and export to a PDF or CSV file and send to others as appropriate. Perhaps you can see if there is a common problems with a group of categories which is the "nature of request". On the right column, you can see the business days over/under SLA.
An important best practice is to never stop the SLA clock from ticking so that problems are not hidden. Giva has the ability to put a ticket on "hold" which is a type of designation whereby the amount of time the ticket was on "hold" is automatically calculated and booked into the ticket history as a note when the ticket is taken off "hold". So, if a tickets is out of SLA you can easily trace this back to a specific reason. Also, Administrators have the ability to back date the close of a ticket and a reason is required. There is also a report that shows tickets where the close was backdated.
Download the webinar slides: Metrics For IT Help Desk & Customer Service Organizations