job taking more time on some days

Hi All,

I have a report (job) which gives cummulative sales figures , cummulative GL account figures and their difference for the give year .

This runs on daily basis.

We have observed that the job runs for 2 hours on some days and 1 hour on some days.

Please help with the reason for this delay.

PFB job run details on various days.

Sno  date              time taken

1. 05.11.2015 0:48:23
2. 06.11.2015 0:51:34
3. 07.11.2015 0:58:32
4. 08.11.2015 0:53:49
5. 09.11.2015 0:50:36
6. 10.11.2015 1:48:30
7. 11.11.2015 1:49:50
8. 12.11.2015 1:55:05
9. 13.11.2015 0:48:44

PS : pattern is, it runs for 2/3 hours continuously for  alternate 3/4 days