An object-oriented temporal model

The representation of complex objects anel behaviors (state transition s) in infmmation systems is a central issue in software engineering. In an infonnation system, supported by a conventional database, the only available state is the set of present values. The object's behavior is controlled by integrity constrains defining only the valid ~;tates. Almost all the representation of the dynamic evolution is lost in the traditional modeling process. In this paper the main concern is to present the extensions made on an ObjectOiiented Model, the F-ORM model [DeAntonellis 91 J to expand the representation o f the object's evolution and to support the teniporal aspects involved. Temporal object-oriented rnodels can be used to specify behavioral requirements of information systems. Four different model ing concepts are defined to represent temporal information: ( l) a set o f temporal data types anel their associated function s, to be used in properties' definitions; (2) time stamps assoei ateei to instances anel to dynamic properties; (3) a special null value for attribute values outside the validity period; and (4) temporal conditions added to rules, written in a temporal logic language. An example showing the use of the Temporal F-ORM is developed