Process Modelleing

I have a flow in process model where each and every subprocess of export to sql runs in sequence(synchronus also) following activity chaining . Once flow is done(when it is success and taking fv!processinfo as a reference) i will show a link to dowload  document which has data generated from sql .But, strangely i am seeing that without completiion of process model in backend that document link is enabled for users where some data is missing beacuse of that.

What makes that document download option is enabling though process model is still running in backend? What makes onsuccess parameter of a!startprocess is not working though i am saving fv!processinfo to 

know when to enable that dowload option?

Can someone pls help on this?