Method integration with formal description techniques

Formal description techniques (FDTs) such as VDM, Z, LOTOS, etc are powerful to develop safety-critical systems since they have strict semantics and mathematical reasoning basis. However, they have no methods or guides how to construct specifications unlike specification and design methods such as Object-Oriented Modeling and Technique (OMT), and that makes it difficult for practitioners to compose formal specifications. One of the solutions is to connect formal description techniques with some existing methods. This paper discusses a technique how to integrate FDTs with specification and design methods such as OMT so that we can have new methods to support writing formal specifications. The integration mechanism is based on transformation rules of specification documents produced following methods into the descriptions written in formal description techniques. The transformation rules specify the correspondences on two meta models; of methods and of formal description techniques, and are described as graph rewriting rules. As an example, we pick up OMT as a method and LOTOS as a FDT and define the transformation rule on their meta models.