A New Modular Petri Net for Modeling Large Discrete-Event Systems: A Proposal Based on the Literature Study

Petri net is a highly useful tool for modeling of discrete-event systems. However, Petri net models of real-life systems are enormous, and their state-spaces are usually of infinite size. Thus, performing analysis on the model becomes difficult. Hence, slicing of Petri Net is suggested to reduce the size of the Petri nets. However, the existing slicing algorithms are ineffective for real-world systems. Therefore, there is a need for alternative methodologies for slicing that are effective for Petri net models of large real-life systems. This paper proposes a new Modular Petri Net as a solution. In modular Petri net, large Petri net models are decomposed into modules. These modules are compact, and the state spaces of these modules are also compact enough to be exhaustively analyzed. The research contributions of this paper are the following: Firstly, an exhaustive literature study is done on Modular Petri Nets. Secondly, from the conclusions drawn from the literature study, a new Petri net is proposed that supports module composition with clearly defined syntax. Thirdly, the new Petri net is implemented in the software GPenSIM, which is crucial so that real-life discrete-event systems could be modeled, analyzed, and performance-optimized with GPenSIM.

Download Full-text

Fault Detection, Isolation and Characterisation for Discrete Event Systems Based on Petri Nets Models

Advances in Civil and Industrial Engineering - Intelligent Industrial Systems ◽

10.4018/978-1-61520-849-4.ch014 ◽

2010 ◽

pp. 387-416

Author(s):

Dimitri Lefebvre ◽

Edouard Leclercq ◽

Souleiman Ould El Mehdi

Keyword(s):

Petri Nets ◽

Petri Net ◽

Discrete Event Systems ◽

Discrete Event ◽

Practical Interest ◽

Transportation Systems ◽

Intermittent Faults ◽

Event Systems ◽

Stochastic Time

Petri net models are used to detect and isolate faults in case of discrete event systems as manufacturing, robotic, communication and transportation systems. This chapter addresses two problems. The first one is the structure designs and parameters identification of the Petri net models according to the observation and analysis of the sequences of events that are collected. Deterministic and stochastic time Petri nets are concerned. The proposed method is based on a statistical analysis of data and has a practical interest as long as sequences of events are already saved by supervision systems. The second problem concerns the use of the resulting Petri net models to detect, isolate and characterize faults in discrete event systems. This contribution includes the characterization of intermittent faults. This issue is important because faults are often progressive from intermittent to definitive and early faults detection and isolation improve productivity and save money and resources.

Download Full-text

Equivalent and Efficient Optimization Models for an Industrial Discrete Event System with Alternative Structural Configurations

Complexity ◽

10.1155/2018/5341346 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Juan-Ignacio Latorre-Biel ◽

Emilio Jiménez-Macías ◽

Mercedes Pérez de la Parte

Keyword(s):

Petri Nets ◽

Petri Net ◽

Discrete Event Systems ◽

Discrete Event ◽

Discrete Event System ◽

Optimization Techniques ◽

Event System ◽

Event Systems ◽

Structural Configurations ◽

Computational Resources

Discrete event systems in applications, such as industry and supply chain, may show a very complex behavior. For this reason, their design and operation may be carried out by the application of optimization techniques for decision making in order to obtain their highest performance. In a general approach, it is possible to implement these optimization techniques by means of the simulation of a Petri net model, which may require an intensive use of computational resources. One key factor in the computational cost of simulation-based optimization is the size of the model of the system; hence, it may be useful to apply techniques to reduce it. This paper analyzes the relationship between two Petri net formalisms, currently used in the design of discrete event systems, where it is usual to count on a set of alternative structural configurations. These formalisms are a particular type of parametric Petri nets, called compound Petri nets, and a set of alternative Petri nets. The development of equivalent models under these formalisms and the formal proof of this equivalence are the main topics of the paper. The basis for this formal approach is the graph of reachable markings, a powerful tool able to represent the behavior of a discrete event system and, hence, to show the equivalence between two different Petri net models. One immediate application of this equivalence is the substitution of a large model of a system by a more compact one, whose simulation may be less demanding in the use of computational resources.

Download Full-text

Petri nets properties related to the unboundness and analyzed using coverability multigraph

Journal of Applied Mathematics Statistics and Informatics ◽

10.2478/jamsi-2014-001 ◽

2014 ◽

Vol 10 (2) ◽

pp. 51-67 ◽

Cited By ~ 1

Author(s):

Branislav Hrúz ◽

Iveta Dirgová Ľuptáková ◽

Miroslav Beňo

Keyword(s):

Petri Nets ◽

State Space ◽

Petri Net ◽

Discrete Event Systems ◽

Discrete Event ◽

System Model ◽

Reachability Graph ◽

Reachability Set ◽

Event Systems ◽

System States

Abstract Petri nets represent a powerful tool for modeling the discrete event systems. The Petri net markings correspond to the system states. The infinity of the marking set means that the Petri net is unbounded and this may be the sign of an incorrect system model. In that case instead of the reachability set and the reachability graph the coverability set and the coverability multigraph can be used to represent the Petri net state space. A systematic way of building the notion of the coverability set and coverability multigraph based on the notion of the ω -marking is given in the paper. Algorithm for its construction is introduced. Then the use of the coverability multigraph for the analysis of several properties of the unbounded Petri nets is described.

Download Full-text