Why Don't People Use Formal Methods?

Formal methods—techniques for mathematically proving software correctness—remain rarely used in practice despite their potential benefits, partly because the field lacks unified terminology and clear communication about what formal methods actually entail. The author distinguishes between formal specification and verification applied to both code and design, noting that even high-assurance software like medical devices rarely employs these techniques, contrary to common assumptions. The barriers to adoption are more nuanced than simple cost arguments and require understanding the historical development and practical limitations of formal methods.