Safety and Reliability of Software Based Systems contains papers, presented at the twelfth annual workshop organised by the Centre for Software Reliability. Contributions come from different industries in many countries, and provide discussion and cross-fertilisation of ideas relevant to systems whose safety and/or reliability are of paramount concern. This book discusses safety cases and their varying roles in different industries; using measurement to improve reliability and safety of software-based systems; latest developments in managing, developing and assessing software intensive systems where reliability and/or safety are important considerations; and practical experiences of others in industry.