Scrum Questions

Hi,

Here my thoughts:

1. DoD is a living document. It changes, usually during retrospectives, with introduction of new practices for higher quality (i.e. technical practices). It influences the team estimated velocity for the next sprint - how many Story Points the team think that could deliver.

2. The Development Team can change its Sprint

From the Scrum Guide: "As new work is required, the Development Team adds it to the Sprint Backlog. As work is
performed or completed, the estimated remaining work is updated. When elements of the plan
are deemed unnecessary, they are removed. Only the Development Team can change its Sprint
Backlog during a Sprint."

3. When respects the Definition of Done and is accepted by the Product Owner

4. One of the role of the Scrum Master is to coach the team. The team members should understand why it is important to participate on an event, what is the value of that event for the team.
Probably is for the team members is the old power of habit. To change old habits is difficult but not impossible. It starts with agile values and principles, with why we do what we do. It takes time to have the Agile Mindset.
You can do some trainings/presentations for your team regarding the agile values, principles or you can ask a professional agile coach to help you.

From Scrum Guide: "Coaching the Development Team in organizational environments in which Scrum is not yet
fully adopted and understood."

5. Inviting PO and dev team at the scrum events and do an introduction about the importance of the event. Why we do it? What's the value? How can we improve?
Let the dev team and PO discuss and keep the discussion on track.
Do the artifacts available for everybody and work on the clarity: the same understanding. Dev team and PO should have access the product backlog and sprint backlog and the work remaining in the sprint using different tools like burndown chants.
Create an open atmosphere at the retrospectives. Give everybody the time to express her/his feeling. As Scrum Master you can say: Let's go around the table and hear everyone.
Keep the events timeboxed.
Coach the PO and dev team about the importance of the events.
Building trust between dev team and PO.
Work on transparency.
The most important thing I think is for everybody is in the same team: devs, PO. And having the one boat mentality. “Unus pro omnibus, omnes pro uno”

One small addition to 2): Keep in mind that there is flexibility in the Sprint Backlog, the Sprint Goal remains fixed.

From the Guide:

During the Sprint:
- No changes are made that would endanger the Sprint Goal;
- Quality goals do not decrease; and,
- Scope may be clarified and re-negotiated between the Product Owner and Development Team as more is learned.

If the Sprint Goal becomes obsolete, the Product Owner may cancel the Sprint - which should be a rare exception, however.

Also note that the Sprint Backlog consists of WHAT to do in order to achieve the Sprint Goal (the Product Backlog Items) as well as HOW to do it, which may relate to a level of tasks.

Guide:

The Sprint Backlog is the set of Product Backlog items selected for the Sprint, plus a plan for delivering the product Increment and realizing the Sprint Goal. The Sprint Backlog is a forecast by the Development Team about what functionality will be in the next Increment and the work needed to deliver that functionality into a “Done” Increment.

For 1) I agreed with Daniel, in addition to what he mentioned i want to state statement from Scrum Guide:
"During each Sprint Retrospective, the Scrum Team plans ways to increase product quality by adapting the definition of “Done” as appropriate."