11. Conclusions on method B

The B method, which is constantly evolving, has proved its worth on a number of major industrial projects. It has been used in full on critical projects and in part on others. It has proved its effectiveness, both in terms of the quality achieved and in terms of costs, which have turned out to be lower than might have been feared at the outset, due to the fact that the finished product is achieved more quickly. The limitation of B is mainly linked to the transition from textual to formal specification. B's evolutions at system level enable us to go further back in the specification, and therefore to work not at software specification level, but at system specification level. The B methodology certainly represents an initial investment, but one that can be largely recouped later on. Engineering adaptation to integrate such a method should not be overlooked, and precautions must be taken to...