This book is a result of the European Experience Exchange (EUREX) project sponsored by the European Systems and Software Initiative for Software Best Practice in Europe. The EUREX project analyzed the industrial and economic impact and the similarities and differences between and among more than 300 Software Process Improvement Experiments sponsored by the EU.The current volume offers a variety of perspectives on software quality issues resulting from that analysis, including testing, verification and validation. This area represents one of the "great unknowns" in software development in the sense that many organisations, especially small and medium enterprises, have no purposeful process addressing these issues. As a result, this book is particularly meaningful for software practitioners in such enterprises, including both developers and line managers.