I'm unclear what you're asking.

From K2's prespective the status will be completed if there's no further events in the workflow. So what exactly do you want to "set"?

If it's just that you don't have anything to point your "Approve" line rule to because you don't need to do anything, then using a Placeholder event is fine.  Are you having some issue with it?

Thank you Victoria for your response. I am puzzled too with what am I suppose to do at the Process Complete Activity  . If the user submit the form at the previous activtity with 'Approve' action, it advances to the next activity (as seen -HKMY process Completed). If I put the placeholder event that does nothing, does it mean that process instance will set its status to Complete ? From the reporting perspective, I want to know that -that process instance has been completed when it hits that HKMY-Process Completed Activity.

Thank you,

Your understanding is correct. K2 workflows do not require that you explicitly define an end point. They execute until there is no additional work to be completed. 

If you require a clearly defined end point for your process, you would do as you mentioned and put an activity in your process called "END" or "COMPLETE" or whatever terminology you prefer. That activity will only need to contain a placeholder event so that the process will compile. 

What this will give you is when looking at a process instance report and seeing the order of execution of activities you will see the activity called END assuming that you have all the possible paths that represent points in the process where it could terminate have lines that flow to the "END" activity.

The actual status of the process will be complete but from an activity stand point if you reached the END step assuming no flaws in logic you could be certain your process was indeed completed. 

Hope this helps.

S.