Formal methods

Formal methods are mathematical techniques used in software engineering and hardware engineering to define precisely the behavior of software, hardware, and network systems. The aim of formal methods is to ensure that software, hardware, and networks interact in a desired, secure fashion. Formal methods use language-based and mechanism-based techniques to check for consistency, completeness, and accuracy in various levels of abstraction.

Formal methods were first used in the 1960s in aerospace, radio engineering, and nuclear reactor control systems as a way to guarantee correctness of the software and hardware system integration. In the late 1970s and 1980s formal methods began to be used in the software engineering field to check for bugs in large and complex software systems.

Language-based formal methods use a formal language to describe the specification of the software and hardware system. Common formal languages used for formal methods include TLA+, Z, and NuSMV. The formal language is used to specify the requirements of a system and the system’s behavior. It must be precise and unambiguous, and must be verified against the software or hardware system.

Mechanism-based formal methods use formal methods of mathematics, such as set theory, process algebras, and modal logics. This approach provides a rigorous foundation for the analysis and verification of the behavior of a software and hardware system and is often applied in safety-critical applications in the Aerospace, Automotive, Railway, and Medical device industries.

Formal methods have also been used to develop secure systems, as they can be used to verify that a system meets security requirements. Through the use of formal methods, it is possible to detect bugs, which can have serious consequences if not addressed before the system is released.

Formal methods are a crucial part of software engineering, hardware engineering, and cybersecurity, and are used to ensure the reliability of systems and their components. The use of formal methods reduces system development time by ensuring that the system is designed and built correctly.