Agile methodologies evolved to cope with the changing requirements in management of software projects, in an effort to increase bring business value of products and create higher client satisfaction. At the heart of agile methodologies lies the agile project teams. Therefore, success of agile projects depend on the performance of project teams. In contrary to the driving forces that foster performance of teams, there are barriers that limit their performance and productivity. In this book, factors that limit the performance of teams operating in agile software projects are studied. Qualitative data, collected from interviews with agile project managers is used to identify and present various barriers grouped under three main topics: Interaction and personal perspective, material perspective and agile process perspective.