A lot has been written about roles and responsibilities in Scrum but the topic is still ambiguous. The Scrum Guide is saying that there is Product Owner, Scrum Master, and The Team. But what is The Team? Developers and testers only? What about business analysts? What about Product Managers on the business side who make prioritization decisions? What about Development Managers? QA Managers? Dev Leads? Operations? There is no stated role for them in Scrum.
This ambiguity is sometimes a reason for people in the roles listed above to fear and resists Agile. However, they are the ones who should embrace it because they will benefit significantly and will get seats at the table with Agile transformation, just not at the implementation team level.
Let's address the three primary roles first. According to the Scrum Guide, "The Scrum Team consists of a Product Owner, the Development Team, and a Scrum Master. Scrum Teams are self-organizing and cross-functional. Self-organizing teams choose how best to accomplish their work, rather than being directed by others outside the team. Cross-functional teams have all competencies needed to accomplish the work without depending on others not part of the team. The team model in Scrum is designed to optimize flexibility, creativity, and productivity." This does not mean that everyone on the team should be fully cross-functional, but it does mean that team as a whole should be able to provide end-to-end functionality, i.e. if you have web services team and UI team separately, they are not cross-functional.
"The Product Owner is responsible for maximizing the value of the product and the work of the Development Team. " Check out this brilliant video by Henrik Kniberg on the Product Owner role.
"The Scrum Master is responsible for ensuring Scrum is understood and enacted. Scrum Masters do this by ensuring that the Scrum Team adheres to Scrum theory, practices, and rules. The Scrum Master is a servant-leader for the Scrum Team. The Scrum Master helps those outside the Scrum Team understand which of their interactions with the Scrum Team are helpful and which aren’t. The Scrum Master helps everyone change these interactions to maximize the value created by the Scrum Team." Check out this article on the details of the Scrum Master role.
What about Product Managers? All of them are definitely stakeholders so Product Owner will take their opinion into account while prioritizing, and will communicate back to them. According to a well-known Scrum metaphor, they are "chickens" but not "pigs".
What about Business Analysts? Many of those are very successful in their transition to Product Owner, but for the time being they are working as Product Owner proxies collecting information and populating the product backlog.
Now, dev leads are a tricky situation. Make an effort to remove them from a planning session where they estimate for everyone and start discussion from their own opinion. Dev leads are a great asset to a team as a team member not a manager or a decision maker for others. They will take over technical user stories or be a stakeholder in those and become a crucial team member with the same decision power as anyone else on the team.
Managers sometimes want to control their employees, so we have to be mindful about any signs of command and control. In Scrum managers have a distinct role to support roll out of best practices in their area of expertise across the organization, whether it is testing or development. In many organizations though I saw successful managers becoming members of their cross-functional Agile teams and doing hands on work along with everyone else on the team. Either way, there is always a role for those who want to contribute and who are interested in bringing value in their area of expertise.
But most importantly, Scrum team members irrespective of their role on the team are decision makers on topics within their domains and active participants in any analysis and brainstorming session on their Agile implementation. No Agile Coach or Scrum professional can decide it for them. Bring them to the table, and you will be positively surprised by their thoughtfulness, creativity, and subject matter expertise!