Rede de petri com temporização nebulosa.

Abstract

We present an extension to the Petri net model, with the objective of characterize temporal constraints. In this extension, the positive aspects of extensions deterministic and stochastic are combined in a complementary way, that is, the extended Petri net suitable for modeling systems in real time and for making systems performance analysis. The extension, called the Nebula Timed Petri Net - FTPN, uses an approach based on set theory. foggy. In the FTPN model, the tokens carry a fuzzy time function that indicates the possibility of its existence at a certain place at a given instant of time. Fuzzy time intervals are still associated with transitions, providing the representation of temporal constraints. To define an approach to modular time analysis of complex systems, the FTPN concept is integrated with a structuring tool called G-Net. As a result of integration, we can divide a complex system into subsystems that will be studied in isolation and the results combined to determine the overall solution. The integrated tool, together with a modular time analysis methodology, is used to introduce time-dependent fault tolerance properties in real-time distributed system design. We use Fuzzy Time G-Nets to represent fault tolerant schemes and to consider failures in advance, in real time distributed systems. In addition, we present a graphical representation, TGIG, for the interaction between G-Nets. This graph represents runtime for each G-Net, taking into account the interaction between G-Nets in a G-Nets system. From this graph, some performance indices can be easily obtained.