Most CRM systems I have seen have a mixture of workflow and dialog owners, usually the person who created them. But this could lead to a problem, consider the scenario when a key employee leaves and your IT team are a little over zealous in removing their computer access. Suddenly all or at least some of your business processes stop working, and you might not even notice for a while. Disaster!
It makes sense to assign all your workflows and dialogs to a single, ideally non-employee user, or at least an employee who will never leave to stop this happening.
A disadvantage of re-assigning a workflow to a new user is that the workflow will need to be deactivated as part of the assignment, then manually re-activated. For a live system this might mean small disruptions in service, or a long boring out of hours session if you are tidying up and have a lot of workflows to assign.
A much simpler method is to simply log in as the new owner of the workflow and assign them to yourself. This has the advantage that they can be done in bulk and the workflows won't be deactivated.
So to do this log in as the new user. (The new user must have rights to run these tasks)
Then open the list of Activated Processes.
To assign an individual workflow, or multiple workflows by selecting them in the list then press the button.
You will see this dialog.
Then press Assign.
After a few moments the workflows will be assigned to the new user.
This is by far the least troublesome method.
When a user creates a workflow it is good practice to set the owner of the workflow when it is first created, and the easiest way is to go to the Administration tab of the workflow designer and update the Owner in there.