An object-oriented temporal model

Abstract

The representation of complex objects and behaviors (state transitions) in information systems is a central issue in software engineering. In an information 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 states. 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 Object-Oriented Model, the F-ORM model [11] to expand the representation of the object’s evolution and to support the temporal aspects involved. Temporal object-oriented models can be used to specify behavioral requirements of information systems. Four different modeling concepts arc defined to represent temporal information: (i) a set of temporal data types and their associated functions, to be used in properties’ definitions; (ii) time stamps associated to instances and to dynamic properties; (iii) a special null value for attribute values outside the validity period; and (iv) temporal conditions added to rules, written in a temporal logic language. An example showing the use of the Temporal F-ORM is developed.