Formal methods and dependability assessment

Formal methods are increasingly used for system development and their potential advantages for dependability assurance have been recognized. However, there has so far been no hard evidence to either support or refute the efficacy of formal methods in this respect. This paper discusses how the dependability of systems can be affected by the tree of formal methods in two respects. First, how and why formal methods can help ensure the dependability of systems, and second what uncertainties can affect their effectiveness in achieving dependability. Issues related to the assessment of formal methods such as assessment criteria an assessment model and the establishment of evaluation experiments are discussed.<>