Formal methods are mathematically-based techniques for the specification, development and verification of software and hardware systems. The term has been applied to a range of notations, theories and tools. As the recent history shows, there is no doubt that some of these rigorous methods have already had a significant impact on practical applications of computing. Moreover, formal methods continue to incorporate new system design paradigms, in an attempt to expand their applicability. In this spirit, this panel aims at discussing the underlying principles of formal methods that make them contribute to increasing the quality and reliability of a design, as well as showing their relation to practical problems, and their potential for the future.