I am using parallel processing.

```
CALL FUNCTION 'ZABC' STARTING NEW TASK taskname
          DESTINATION IN GROUP srv_grp PERFORMING come_back ON END OF TASK
EXPORTING
 ...
EXCEPTIONS
...
.

```

I am calling this FM inside a loop. sometimes, my records are skipped. I am not getting a desired output. Sometimes 2000 records are processed and sometimes 1000. The numbers are varying. what can be the problem ? Can you provide me some cases where records can be skipped in parallel processing ?