The aim of the book is to develop the bridge between two 'islands': Software Architecture and Requirements Engineering. However, in Software engineering, there is another gap that needs to be bridged between two different types of communities: industry and academia. Industrial practitioners work under hard constraints and often do not have the luxury of trying out research results, let alone embedding them in their everyday practice. In contrast, academic researchers face the pressure of 'publish or perish' and often struggle with finding the right industrial context in which to validate their work. Nevertheless, when the right synergy is established between the two communities, there can be substantial progress of the state of the art.