Many large organizations currently operate by creating project teams of people who formally report into other parts of the organization. This matrixed organization is meant to allow people to develop centers of excellence around a specialization and at the same time to implement a system of checks and balances. However, this type of organization also often encourages sub-optimal behavior by narrow performance measures and incentives (narrow to the area of specialization).
Consider using de-matrixed teams if you are finding that people on your teams are having a hard time collaborating, or if people are refusing to do work outside their area of specialization, or if people are doing really well inside their center of excellence but seem to have real problems making projects succeed.
What is a de-matrixed team? A de-matrixed team is constituted by having all members of the team report to a primary stakeholder of the endeavor. It is still possible, and often wise, to maintain centers of excellence, but team members no longer report into these centers of excellence. Instead, the centers of excellence become a source of support for teams that have specific needs (skills, infrastructure, etc.).