Blog posts by Esther Derby and Mike Cohn focus on two different aspects of the staffing of Agile teams.
In her blog post, Derby makes a case for stability with respect to Agile team membership. According to Derby, moving people into and out of teams has negative affects that include miscommunication, misunderstanding, and lack of mutual accountability. She writes:
Team members can't be mutually accountable if they don't know who makes up "we" when they commit to deliver.
Mike Cohn asserts that, despite the self-organizing nature of Agile teams, the teams themselves should not possess the exclusive right to remove their own members. According to Cohn, the leadership of the organization must itself take responsibility for team composition.
Cohn bases his assertion, in part, on the work of Glenda Eoyang, referring specifically to her Container-Difference-Exchange (CDE) model of self-organization. According to Cohn, one of the responsibilities of leaders is to exert infuence over Agile teams by making adjustments to the team's boundaries, as established by the organization. He writes:
For example, over time and through attrition a team might have become too homogeneous. An astute product owner, functional manager, or even ScrumMaster might counter that by adding two new team members with radically different backgrounds, skills, decision-making styles, or so on. Doesn't it seem possible—likely even, in this example—that a team might have a knee-jerk reaction and vote the new, nonconforming individuals off the team, negating the work of the leader who deliberately added them? Ultimate authority for team composition, therefore, must reside with the leadership of the organization.