For large companies comprised of multiple product groups or resulting from growth through mergers and acquisitions, the "S" word, synergy, is touted as a great strategic advantage, but more often than not turns out to be a mirage, as managers haggle over turf and the parent company lacks the skills or commitment to recognize, support, and sustain collaboration. So how does a company become more than the sum of its parts? Here, international strategy gurus, Andrew Campbell and Michael Goold, offer an incisive and highly practical approach to overcoming barriers to synergy, evaluating opportunities within and outside the company, establishing appropriate roles for corporate headquarters and business units, and fostering a commitment to collaboration at all levels of the organization.