CPS job went to assigned status

Hi Team,

We recently had an issue where one of the periodic job(which runs every five mins) was in assigned status .It didn't run for one whole day until user identified and reported .After that we re-submitted the job and it started working fine

Could you please suggest what could be reason for a job in CPS to be in assigned status ,where can we check logs.In SAP SM21 i couldn't see any logs

Also is there a way where we can get an alert/notification mail in case a job stays in assigned status or not running

Regards,

Murali