a particular kind of mathematically-based technique for the specification, development and verification of software and hardware systems.
Formal methods are a particular kind of mathematically-based techniques for the specification, development and verification of software and hardware systems.
The use of formal methods for software and hardware design is motivated by the expectation that, as in other engineering disciplines, performing appropriate mathematical analysis can contribute to the reliability and robustness of a design.
Formal methods are best described as the application of a fairly broad variety of theoretical computer science fundamentals, in particular logic calculi, formal languages, automata theory, and program semantics, but also type systems and algebraic data types to problems in software and hardware specification and verification.
See also proof-techniques.