Within the Scrum Framework three roles are defined:
The Scrum Team
Scrum Product Owner
Each of these roles has a defined set of responsibilities and only if they fulfill these responsibilities, closely interact and work together they can finish a project successfully.
Scrum Roles & Stakeholders
The Scrum Team
Within the Scrum Framework all work delivered to the customer is done by dedicated Scrum Teams. A Scrum Team is a collection of individuals working together to deliver the requested and committed product increments.
To work effectively it is important for a Scrum Team that everyone within the team
follows a common goal
adheres the same norms and rules
shows respect to each other
When setting up a new Scrum Team one always has to keep in mind that no new team will deliver with the highest possible performance right from the beginning. After setting up the team it has to go through certain phases as described by the Tuckman-Model: Forming, Storming, Norming, Performing.
How long it takes until the Scrum Team is in the Performing Phase depends on the team, and yet it normally takes about 3 Sprints until the teams is mature enough to deliver their results in a predictable way.
Characteristics of a Scrum Team
Scrum Teams always have the following characteristics:
Team members share the same norms and rules
The Scrum team as a whole is accountable for the delivery
The Scrum Team is empowered
It is working as autonomous as it is possible
The Scrum Team is self organizing
The skills within the Scrum team are balanced
A Scrum Team is small and has no sub-teams
The people within the Scrum Team work full time in the team
People are collocated
Rules & Norms
Of course their environment defines some of the norms the teams have to follow, but some rules and norms are developed during the Norming phase. This set of common rules is quite important. Otherwise the team members would have to constantly waste valuable time to switch between different value systems and rule sets. Examples for such norms and rules are:
time and location of the Daily Scrum Meeting
the Definition Of Done (DoD) used to decide if work is finished or not
tools to use
The Scrum Team as a whole is responsible to deliver the committed delivery in time and with the defined quality. A good result or a failure is never attributed to a single team member but always the result of the Scrum Team.
Empowerment & Self organization
The Scrum Team has to be empowered to define
what it will commit to deliver at the end of the sprint
how the expected results have to be broken down into tasks
who will perform the task and in which order they are performed
Only if the Scrum Team is empowered to decide these things it will work with the highest possible motivation and performance.
Balanced set of skill
Individuals within the Scrum Team will most certainly have specialized skills and focus. However to achieve best possible performance it would be optimal to have a balanced set of skills. Only then the Scrum Team will be able to deal with the ever-changing challenges and can act as autonomous as it is possible.
On one hand this means that a Scrum Team should be multidisciplinary (developers, tester, architects etc) right from the beginning. On the other hand this also means that each team member should learn a little bit of each other's specialization, e.g. a if required to finally reach the committed goal a developer should also perform or write tests.
As a consequence this also means that within the Scrum Framework it is not differentiated between e.g. "tester" and "architect", they all share the same title "Scrum Team Member" even if the primary skill is not to develop production code.
Size of the Scrum Team
Scrum Teams are small. The ideal size is 7 +/- 2 people.
If there are more people the communication overhead gets too large and the team should be split into multiple Scrum Teams. These Scrum Teams should be coordinated and communicate with each other but otherwise work independently.
To minimize unnecessary communication overhead each Scrum Team should be collocated. If work has to be spread over multiple locations, independent Scrum Teams should be created.
Responsibilities of the Scrum Team
The Scrum Team and each of the team members has certain responsibilities which have to be fulfilled:
They have to breakdown the requirements, create task, estimate and distribute them. In other words this means that they have to create the Sprint Backlog.
They have to perform the short Daily Sprint Meeting.
They have to ensure that at the end of the Sprint potentially shippable functionality is delivered.
They have to update the status and the remaining efforts for their tasks to allow creation of a Sprint Burndown Diagram.