Who defines the Product Goal?
The Scrum Guide v2020 says this :
The Scrum Team is responsible for all product-related activities from stakeholder collaboration, verification, maintenance, operation, experimentation, research and development, and anything else that might be required.
Does defining the Product Goal considered a product-related activity? If yes, then does it mean the Scrum Team is responsible for defining the Product Goal?
The Scrum Guide v2020 also says this :
The Product Owner is also accountable for effective Product Backlog management, which includes:
Developing and explicitly communicating the Product Goal;
Here it does not say the Product Owner defines the Product Goal, it just says he or she is "accountable" for "developing" the Product Goal.
So the Product Owner defines the Product Goal, or the Scrum Team defines the Product Goal?
Another consideration when reading the Scrum Guide, which is relevant to 'Developing and explicitly communicating the Product Goal' is the paragraph that comes after:
The Product Owner may do the above work or may delegate the responsibility to others. Regardless, the Product Owner remains accountable.
Depending on the situation the Product Owner may define it alone, it may be a collaborative effort amongst the Scrum Team, or it could be 'delegated to others'. In the world of complexity that we live in, there is no best practice and Scrum provides some flexibility to suit the context of the situation.
The key piece is that the Product Owner is accountable if he or she has delegated the definition to others. The product Goal is part of the Product Backlog, and the situation is similar to when the Product Owner delegates the creation of Product Backlog items to others.
So the Product Owner defines the Product Goal, or the Scrum Team defines the Product Goal?
Yes, that's right. One or the other or both, while the Product Owner -- who is on the team -- remains accountable.
Remember the Product Owner is a member of the SCRUM TEAM.
So if the Product Owner is accountable, that is a tightening of the accountability from the Scrum Team, but it is not a contradiction.
I don't have a problem with the Product Owner defining the Product Goal, it's pretty obviously that he has to do it. What's unclear to me is, are the Developers and Scrum Master mandatory in defining the Product Goal too.
Similarly to the Definition of Done, it was the Development Team that defines the DoD, now it is the Scrum Team that defines the DoD.
What's unclear to me is, are the Developers and Scrum Master mandatory in defining the Product Goal too.
It's mandatory that they are franchised in its definition, because it represents a joint commitment. Scrum is minimally prescriptive, and establishes no mandatory conditions about how this is implemented.
Similarly to the Definition of Done, it was the Development Team that defines the DoD, now it is the Scrum Team that defines the DoD.
"Done" needs to meet the need of the customer - which is what the Product Owner is there to ensure.