Is it possible to trigger the workflow whenever dependent component edited? E.g. Lets say workflow has been applied on the article component which include image component linking, normal component linking. I want my article workflow to be trigger whenever content author edited the linked image component directly.
Yes, it's possible since 2011 I believe. You can create event handler which will kick in when linked component is saved. Inside the handler you can figure out what related items should have workflow triggered and create a new process instance with those items.