Um método baseado em redes de petri para modelagem de bancos de dados em tempo-real.

Abstract

The methods available to describe the conceptual model of conventional database systems cannot be directly applied to describe the model of real-time database systems, since these models do not provide mechanisms to represent the temporal restrictions that exist in such systems. Also, most of the available models focus on the representation of static properties of the data. On the other hand, complex systems, such as real-time databases, require that dynamic properties for data and information be modeled as well. Therefore, it is necessary the development of methods for the design of real-time databases supporting the modeling of both static and dynamic aspects of systems. The main objective in this work is to define a method with formal basis for the modeling of real-time database systems, in the context of flexible manufacturing systems and industrial automation in general. The application of such a method results in two models: an object model, that is used to model the static aspects of a system, and a process model, used to model the dynamic aspects of a system. The object model is based on the object model of the OMT (Object Methodology Technique), and on the real-time object oriented data model RTSORAC, (Real Time Semantic Objects Relationships and Constraints), whereas the process model is based on a high level Petri net named ECPN (Extended Coloured Petri Nets), developed in this work.