Thanks, Mark,

for the quick help, i was looking for First Level Response as a custom field. which gives me FLR if SLA is not configured for another task, like SC_Task.

I quite agreed with you point if we have SLA configured for incident we will get Business Elapsed Time as FLR But what about for those Task or request where SLA is not there I have to get there respective FLR  help me this is information.