It is called a test policy.
- Improve Quality Services made a one pager for a test policy. See page 6 of the following presentation:
https://conference.eurostarsoftwaretesting.com/wp-content/uploads/w5.pdf
The presentation is heavily geared to waterfall, but it can be adapted to Scrum. - Logica (now known as CGI) published a book TestGrip.
- Sogeti published a rough overview on the web.
Quality and test policy | DevOps | TMap