A FORMAL SEMANTICS FOR OBJECT MODEL DIAGRAMS

Informal software development techniques, such as the Object Modeling Technique (OMT), provide the user with easy to understand graphical no tations for expressing a wide variety of concepts central to the prese ntation of software requirements. OMT combines three complementary dia gramming notations for documenting requirements: object models, dynami c models, and functional models. OMT is a useful organizational tool i n the requirements analysis and system design processes. Currently, th e lack of formality in OMT prevents the evaluation of completeness, co nsistency, and content in requirements and design specifications. A fo rmal method is a mathematical approach to software development that be gins with the construction of a formal specification describing the sy stem under development. However, constructing a formal specification d irectly from a prose description of requirements can be challenging. T his paper presents a formal semantics for the OMT object model notatio ns, where an object model provides the basis for the architecture of a n object-oriented system. A method for deriving modular algebraic spec ifications directly from object model diagrams is described. The forma lization of object models contributes to a mathematical basis for deri ving system designs.