Mate and Silva, both of Universidad Politecnica de Madrid, define a sociotechnical system as a "complex inter-relationship of people and technology" and they contend that requirement engineering is the discipline most suited to achieving successful sociotechnical system development. The contributors to this volume pave the way to that success in their discussions of the basic elements of requirement engineering, its challenges, and techniques for solving the complex problems that arise in sociotechnical system development.