What is "b-method"

The B method is a method of software development based on B, a tool-supported formal method based on an abstract machine notation, used in the development of computer software. It was originally developed by Jean-Raymond Abrial in France and the UK. B is related to the Z notation (also originated by Abrial) and supports development of programming language code from specifications. B has been used in major safety-critical system applications in Europe (such as the Paris Métro Line 14). It has robust, commercially available tool support for specification, design, proof and code generation.

Compared to Z, B is slightly more low-level and more focused on refinement to code rather than just formal specification — hence it is easier to correctly implement a specification written in B than one in Z. In particular, there is good tool support for this.

Recently, another formal method called Event-B has been developed. Event-B is considered an evolution of B (also known as classical B). It is a simpler notation, which is easier to learn and use. It comes with tool support in the form of the Rodin tool.