Software product lines represent perhaps the most exciting paradigm shift in software development since the advent of high-level programming languages. Nowhere else in software engineering have we seen such breathtaking improvements in cost, quality, time to market, and developer productivity, often registering in the order-of-magnitude range. While the underlying concepts are straightforward enough – building a family of related products or systems by planned and careful reuse of a base of generalized software development assets – the devil can be in the details, as successful product line practice can involve organizational change, business process change, and technology change. The authors ideally combine academic research results with industrial real-world experiences, thus presenting a broad view on product line engineering so that both managers and technical specialists will benefit from reading it. After presenting a common framework for the description of the industrial case studies, they capture the wealth of knowledge that eight companies have gathered during the introduction of the software product line engineering approach in their daily practice. After reading this book, you will understand all the relevant aspects, regarding business, architecture, process, and organizational issues, of applying software product line engineering. If you consider using a product line approach in your organization, or if you want to improve your current practices you will find a rich set of useful information at your fingertips – from practitioners to practitioners.