This book systematically identifies the lack of methodological support for development of
requirements and software architecture in the state-of-the-art. To overcome this deficiency
the QuaDRA framework is proposed as a problem-oriented approach. It provides an instantiation
of the Twin Peaks model for supporting the intertwining relationship of requirements and
software architecture. QuaDRA includes several structured methods which guide software
engineers in quality- and pattern-based co-development of requirements and early design
alternatives in an iterative and concurrent manner.
