Action on workitem SWW_WI_DEADLINE_CALLBACK

Hi All,

I have developed a workflow in which i have created deadline monitoring on Decision Step for Latest End step.and selected Modeled step

and after deadline has reached , i have defined a mail step to send mail to approver after Modeled branch.

In the log , I can see Deadline has reached and there is Action On Workitem in the Log -> SWW_WI_DEADLINE_CALLBACK is showing.

What does it mean?

And Even though deadline has reached step under the Modeled branch has not executed nor it is showing in the workflow log.

Please help?

Thanks,

Arpita