The Daily Scrum is an event for and by the Developers. They can choose whatever structure and technique they want, as long as they focus on the progress toward the Sprint Goal and produce an actionable plan for the next day of work12. The Scrum Master, the Product Owner, and the person coming in last are not necessarily the ones who should start the Daily Scrum. The person who has the token is a possible technique, but not the only one3.

The Scrum Team consists of one Scrum Master, one Product Owner, and Developers. Within a Scrum Team, there are no sub-teams or hierarchies. It is a cohesive unit of professionals focused on one objective at a time, the Product Goal. The Scrum Master is accountable for establishing Scrum as defined in the Scrum Guide. They do this by helping everyone understand Scrum theory and practice, both within the Scrum Team and the organization. The Product Owner is accountable for maximizing the value of the product resulting from the work of the Scrum Team. They are responsible for creating and communicating a vision, ordering the Product Backlog, and ensuring that the best possible job is done to delight customers. The Developers are the people in the Scrum Team that are committed to delivering a ''Done'' Increment that meets the Definition of Done and the Sprint Goal. They are responsible for managing and organizing their work within the Sprint, collaborating with the Product Owner and the Scrum Master, and applying their skills and creativity to create a product that delivers value to the stakeholders and customers. A Project Manager is not a role in the Scrum Team, as Scrum does not recognize titles for Developers, regardless of the work being performed by the person. There is no need for a Project Manager, as the Scrum Team is self-managing and accountable for delivering value.

The Scrum Guide

The Scrum Team

Professional Scrum Product Owner I Certification

In Scrum, there is only one product and one Product Backlog for a given product. The Product Backlog is the single source of truth for the Scrum Team and the stakeholders. It contains all the requirements, features, functions, enhancements, fixes, and anything else that can deliver value to the customers and users of the product. The Product Backlog is ordered by the Product Owner based on the product vision, goals, and value.

Having multiple Product Backlogs for one product would create confusion, duplication, inconsistency, and waste. It would also make it harder to align the Scrum Teams and the stakeholders on the same product direction and priorities. Therefore, each Scrum Team should not have a separate Product Backlog.

The Product Owner is accountable for maximizing the value of the product resulting from the work of the Scrum Team. The Product Owner is responsible for managing and refining the Product Backlog, collaborating with the stakeholders and the Developers, and ordering the items in a way that best achieves goals and missions. The Product Owner represents the interests of everyone with a stake in the product and ensures that the Scrum Team works on the right things at the right time.

Having multiple Product Owners for one product would create conflicts, overlaps, gaps, and inefficiencies. It would also make it harder to maintain a clear and consistent product vision, strategy, roadmap, and backlog. Therefore, there should be only one Product Owner for one product.

In some cases, when there are multiple Scrum Teams working on one product, it may be necessary to have some form of scaling or coordination mechanism to ensure alignment and collaboration among the teams. However, this does not mean that there should be multiple Product Owners or Product Backlogs. Instead, there should be ways to facilitate communication, feedback, integration, and transparency among the teams and with the Product Owner. For example, some frameworks or practices that can help with scaling Scrum are Nexus, LeSS, SAFe, or Scrum of Scrums.

Scrum Guide: https://www.scrumguides.org/scrum-guide.html

Nexus: https://www.scrum.org/resources/what-is-nexus

LeSS: https://less.works/

SAFe: https://www.scaledagileframework.com/

Scrum of Scrums: https://www.agilealliance.org/glossary/scrum-of-scrums/

The Product Owner is the sole person responsible for managing the Product Backlog and ensuring that the value of the work the Scrum Team performs is understood by everyone involved. The Product Owner is the only person who can cancel the Sprint, although he or she may do so under influence from the stakeholders, the Development Team, or the Scrum Master1. A Sprint can be cancelled before the Sprint time-box is over. Only the Product Owner has the authority to cancel the Sprint, although he or she may do so under influence from the stakeholders, the Development Team, or the Scrum Master. A Sprint would be cancelled if the Sprint Goal becomes obsolete. This might occur if the company changes direction or if market or technology conditions change. In general, a Sprint should be cancelled if it no longer makes sense given the circumstances. But, due to the short duration of Sprints, cancellation rarely makes sense1. Reference:

Scrum Guide

Sprint Cancellation

Can Scrum Master cancel a sprint?