Ideas please

[BlurredVision]

Just looking for some ideas...

I have the following information to report from.. It will verify from record to record.

ENTRY_TYPE Count datetime GROUP_ID
New Problem 1.00 7:21:32AM IT SHIFT OPS
Problem Transfer 2.00 7:21:33AM IT SHIFT OPS
Add Work History 0.00 8:18:21AM NTS
Problem resumed by 0.00 10:16:47AM NTS
Problem Resume Canc 0.00 10:16:57AM NTS
Status Changed 0.00 12:42:02PM NTS
Quick Solution 0.00 12:42:02PM NTS
Problem resumed by 0.00 12:47:21PM NTS
Add Work History 0.00 12:47:58PM NTS
Problem Closed 13:41:39PM NTS

The above is a problem management record. Each line is a entry from the history table(audit trail). I need to find a way check to see if the group 'IT SHIFT OPS' had updated the problem every 30 mins until the problem was closed.

Kinda thinking of doing a 1/2 hour grouping and seach for the group_id 'IT SHIFT OPS' Am I heading in the right direction?

Thanks for any help given..

-Brian