Explanation
When there are multiple teams working on one product, each Scrum Team should not have a separate Product Owner. This is because:
* The Product Owner is accountable for maximizing the value of the product resulting from the work of the Scrum Team. They are responsible for identifying and articulating the Product Goal, which is a long-term objective for the product that guides all the activities of the Scrum Team.
* The Product Owner is the sole person responsible for managing the Product Backlog, which is an emergent, ordered list of what is needed to improve the product. They must ensure that the Product Backlog is transparent, visible, and understood by everyone who needs to work on it.
* Having multiple Product Owners for one product may lead to conflicts, inconsistencies, or confusion among the Scrum Teams and the stakeholders. It may also reduce the alignment, collaboration, and ownership of the product development.
* Instead of having multiple Product Owners, it is recommended to have one Product Owner who works with representatives from each Scrum Team to ensure that they have a shared understanding of the product vision, goals, and priorities. The Product Owner may also delegate some of the Product Backlog management tasks to these representatives, but they remain accountable for the final decisions.
References:
* [Scrum Guide], page 6, section "Product Owner"
* [Scrum Guide], page 11, section "Product Backlog"
* [Scrum Guide], page 10, section "Product Goal"
* [Professional Scrum Product Owner Training], page 6, section "Product Vision"
* [Professional Scrum Product Owner Training], page 9, section "Business Strategy"