Computer Science has made considerable progress in making complex software and hardware systems more reliable. This is a result of practical experience and continuous process improvement on one side and of a better and deeper understanding of the fundamentals of software and system engineering on the other side. Recent encouraging trends are a strong integration of formal techniques with practical industrial development methods and more advanced support tools such as modelling, verification, and model-checking support systems. This active area of research has a relatively short term horizon with respect to transferring technology to industrial applications. This volume is focusing on techniques and the scientific basis for calculation-based development of software and hardware systems as a foundation for advanced methods and tools for software and system engineering. This includes topics of specification, description, methodology, refinement, verification, and implementation. The volume presents new trends and insights reflecting the current state of the art in the scientific foundation of these techniques, since such a foundation is an indispensable prerequisite for advanced development methods.