Grant: Discovery Grants Program - Individual

The long-term objective of this research is the development of efficient methods for modeling and analysis of concurrent systems, i.e., systems in which some events can occur concurrently but there are restrictions of precedence and frequency of such occurrences. Multiprocessor and distributed systems, database systems, communications protocols and networks are examples of such systems. Because of very simple representation of concurrency and synchronization of events, Petri nets have been gaining popularity in modeling and analysis of concurrent systems. Several types of Petri nets "with time" have been proposed on order to take into account the durations of modeled activities, and to use the same models for qualitative and well as quantitative analyses of the modeled systems. However, net models of real-life systems tend to be too complex and too difficult to be dealt with directly (the so called "state explosion problem" of state-based models). Therefore special techniques (and software tools implementing these techniques) are needed for analysis of many realistic models. Short-term objectives of this project include: (i) automatic (or semi-automatic) derivation of net models from specifications of the modeled systems, (ii) efficient analysis methods of derived models, and (iii) development of software tools for generation, analysis and evaluation of net models. All these objectives are complementary in the sense that they refer to different stages of the modeling and analysis process. It is expected that more efficient algorithms and, especially, more user--friendly software tools (which will hide the more advanced aspects of Petri nets) will increase popularity of Petri nets in modeling, analysis and evaluation of complex systems.