We have a very large development group with many teams. For example, we may have 5-6 teams working on one product. In this mode, how can you maintain a common backlog for the product and also track the velocity of each team? Teams also cross over to other products. We want to be able to maintain the velocity outside of the project. Currently the only way we figure this can be done is to align a project with a team which is prohibitive for maintaining a common backlog for the product.