When is the best moment to discuss & define access rights, and what are the steps to be taken?
The below chart shows a step by step approach that can be used as a starting point (although of course it needs to be customized based on the processes of the company/entity it is rolled out in).
You might also be interested by our "User Access Form" available in the Document Control Toolbox:
Other blog articles that might interest you:
Good practices for user access
Controlled and Uncontrolled Documents
Roadmap for implementing Document Control