Follow-up on everything. The conventional wisdom is that teams are most effective when they are small, usually having no more than 15 members, and often between 5 and 10. The most effective teams achieve a balance between the diversity from a larger group and the dedicated focus more easily achievable in small groups. This richness is often needed to achieve the critical mass needed to implement changes and make them stick. The special contribution that a team makes to an organization is the creativity possible from its unique combination of skills, knowledge, experience, and perspectives.
Greater diversity can means greater thoroughness .
However, being thorough often requires the team to expand its scope and make more decisions . A team may not have the time to sort out all its decisions. So limits on the size of a group should be coordinated with limits on the scope of that team's charter. Also, teams may not need to be large if people outside the team can feel included in discussions and decisions. External Customers are individuals or organizations from outside of the organization.