A Formal Object Specification Technique Integrating Object and Functional Model

Abstract

In this paper we introduce a formal object specification technique. We call it OST in analogy to the well-known object modelling technique (OMT), because it adapts the OMT methodology. In order to have a better integration of object and functional model we propose to specify the operations of the functional model in terms of instance diagrams in a rule-based way as it is known from graph transformations. Moreover OST allows complex data constraints in the object model concerning existence and uniqueness of objects and attributes in a specific context. These constraints are described graphically over instance diagrams and they can be ensured automatically within the functional model. The correctness of the mechanism for ensuring the constraints is guaranteed by the formal semantics of OST.