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GreatSPN 1.7: GRaphical Editor and Analyzer for Timed and Stochastic Petri Nets
, 1995
"... This paper describes the GreatSPN 1.7 package for the modeling, validation, and performance evaluation of distributed systems using Generalized Stochastic Petri Nets and their colored extension. The tool provides a friendly framework to experiment with timed Petri net based modeling techniques. It i ..."
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Cited by 95 (17 self)
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This paper describes the GreatSPN 1.7 package for the modeling, validation, and performance evaluation of distributed systems using Generalized Stochastic Petri Nets and their colored extension. The tool provides a friendly framework to experiment with timed Petri net based modeling techniques. It implements efficient analysis algorithms to allow its use on "real" applications, not only toy examples. Developed in a University for non profit purposes, it is distributed free of charge to other universities for educational and research purposes. An overview of the complete architecture of the package is given together with examples of its application. Then the various analysis and simulation modules are described. 1 Introduction GreatSPN 1.7 is a tool for the modeling and analysis of systems, based on the Petri net formalism. In this paper we first briefly describe the historical evolution of the package, which explains the reasons for some implementation choices as well as the intended p...
Numerical Analysis of Superposed GSPNs
 IEEE TRANSACTIONS ON SOFTWARE ENGINEERING
, 1996
"... The numerical analysis of various modeling formalisms profits from a structured representation for the generator matrix Q of the underlying continuous time Markov chain, where Q is described by a sum of tensor (Kronecker) products of much smaller matrices. In this paper we describe such a representa ..."
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Cited by 68 (10 self)
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The numerical analysis of various modeling formalisms profits from a structured representation for the generator matrix Q of the underlying continuous time Markov chain, where Q is described by a sum of tensor (Kronecker) products of much smaller matrices. In this paper we describe such a representation for the class of superposed generalized stochastic Petri nets (SGSPNs), which is less restrictive than in previous work. Furthermore a new iterative analysis algorithm is proposed. It pays special attention to a memory efficient representation of iteration vectors as well as to a memory efficient structured representation of Q. In consequence the new algorithm is able to solve models which have state spaces with several millions of states, where other exact numerical methods become impracticable on a common workstation.
Generalized stochastic Petri nets: A definition at the net level and its implications
 IEEE Transactions on Software Engineering
, 1993
"... Abstmct The original proposals of several stochastic Petri net modeling techniques and of generalized stochastic Petri nets (GSPN) in particular were based mainly on the characteristics of their underlying stochastic processes. This led to the use of GSPN only as a shortened notation for the descri ..."
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Cited by 62 (9 self)
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Abstmct The original proposals of several stochastic Petri net modeling techniques and of generalized stochastic Petri nets (GSPN) in particular were based mainly on the characteristics of their underlying stochastic processes. This led to the use of GSPN only as a shortened notation for the description of stochastic models. Although already quite useful in practice, this approach did not fully exploit the benefits of a Petri net description; in particular, it did not use any of the results of classical net theory. The integration of qualitative net theory results, together with the probabilistic analysis approach, requires a deep structural foundation of the GSPN definition. In this paper, the class of Petri nets obtained by eliminating timing from GSPN models while preserving the qualitative behavior is identified. Structural results for those nets are also derived, thus obtaining the first structural analysis of Petri nets with priority and inhibitor arcs. A revision of the GSPN definition based on the structural properties of the models is then presented. The main advantage is that for a (wide) class of nets, the definition of firing probabilities of conflicting immediate transitions does not require the information on reachable markings (which was, instead, necessary with the original definition). Identification of the class of models for which the netlevel specification is possible is also based on the structural analysis results. The new procedure for the model specification is illustrated by means of an example, which shows the usefulness of the new approach. A net level specification of the model associated with efficient structural analysis techniques can have a substantial impact on model analysis as well. Index TermsConflicts and concurrency, Markovian models, performance modeling, probabilistic specification, stochastic Petri nets, structural Petri net analysis, timed and immediate transitions, transition priorities. I.
Saturation Unbound
 Proc. TACAS
, 2003
"... In previous work, we proposed a "saturation" algorithm for symbolic statespace generation characterized by the use of multivalued decision diagrams, boolean Kronecker operators, event locality, and a special iteration strategy. This approach outperforms traditional BDDbased techniques by ..."
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Cited by 51 (23 self)
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In previous work, we proposed a "saturation" algorithm for symbolic statespace generation characterized by the use of multivalued decision diagrams, boolean Kronecker operators, event locality, and a special iteration strategy. This approach outperforms traditional BDDbased techniques by several orders of magnitude in both space and time but, like them, assumes a priori knowledge of each submodel's state space. We introduce a new algorithm that merges explicit local statespace discovery with symbolic global statespace generation. This relieves the modeler from worrying about the behavior of submodels in isolation.
Petri Net Supervisors for DES with Uncontrollable and Unobservable Transitions
 IEEE Transactions on Automatic Control
, 1999
"... A supervisor synthesis technique for Petri net plants with uncontrollable and unobservable transitions that enforces the conjunction of a set of linear inequalities on the reachable markings of the plant is presented. The approach is based on the concept of Petri net place invariants. Each step o ..."
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Cited by 44 (12 self)
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A supervisor synthesis technique for Petri net plants with uncontrollable and unobservable transitions that enforces the conjunction of a set of linear inequalities on the reachable markings of the plant is presented. The approach is based on the concept of Petri net place invariants. Each step of the procedure is illustrated through a running example involving the supervision of a robotic assembly cell. The controller is described by an auxiliary Petri net connected to the plant's transitions, providing a unified Petri net model of the closed loop system. The synthesis technique is based on the concept of admissible constraints. An inadmissible constraint can not be directly enforced on a plant due to the uncontrollability or unobservability of certain plant transitions. Procedures are given for identifying all admissible linear constraints for a plant with uncontrollable and unobservable transitions, as well as methods for transforming inadmissible constraints into admissib...
Formal Semantics and Analysis of Control Flow in WSBPEL
 PROGRAMMING 67(2/3):PP. 162198. © COPYRIGHT 2007 ELSEVIER
, 2007
"... Web service composition refers to the creation of new (Web) services by combining functionality provided by existing ones. A number of domainspecific languages for service composition have been proposed with consensus being formed around a processoriented language known as WSBPEL (or BPEL). The ..."
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Cited by 30 (5 self)
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Web service composition refers to the creation of new (Web) services by combining functionality provided by existing ones. A number of domainspecific languages for service composition have been proposed with consensus being formed around a processoriented language known as WSBPEL (or BPEL). The kernel of BPEL consists of simple communication primitives that may be combined using controlflow constructs expressing sequence, branching, parallelism, synchronization, etc. We present a comprehensive and rigorously defined mapping of BPEL constructs onto Petri net structures and use this for the analysis of various dynamic properties related to unreachable activities, conflicting messages, garbage collection, conformance checking, and deadlocks and lifelocks in interaction processes. We use a mapping onto Petri nets because this allows us to use existing theoretical results and analysis tools. Unlike approaches based on finite state machines, we do not need to construct the state space and can use structural analysis (e.g., transition invariants) instead. We have implemented a tool that translates BPEL processes into Petri nets and then applies Petrinetbased analysis techniques. This tool has been tested on different examples and has been used to answer a variety of questions.
Distributed statespace generation of discretestate stochastic models
 INFORMS J. COMP
, 1995
"... Highlevel formalisms such as stochastic Petri nets can be used to model complex systems. Analysis of logical and numerical properties of these models often requires the generation and storage of the entire underlying state space. This imposes practical limitations on the types of systems which can ..."
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Cited by 28 (12 self)
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Highlevel formalisms such as stochastic Petri nets can be used to model complex systems. Analysis of logical and numerical properties of these models often requires the generation and storage of the entire underlying state space. This imposes practical limitations on the types of systems which can be modeled. Because of the vast amount of memory consumed, we investigate distributed algorithms for the generation of state space graphs. The distributed construction allows us to take advantage of the combined memory readily available on a network of workstations. The key technical problem is to find effective methods for onthefly partitioning, so that the state space is evenly distributed among processors. In this paper we report on the implementation of a distributed statespace generator that may be linked to a number of existing system modeling tools. We discuss partitioning strategies in the context of Petri net models, and report on performance observed on a network of workstations, as well as on a distributed memory multicomputer.
Fault detection for discrete event systems using Petri nets with unobservable transitions
, 2005
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QPNTool for the Specification and Analysis of Hierarchically Combined Queueing Petri Nets
 BAUSE (EDS.) QUANTITATIVE EVALUATION OF COMPUTING AND COMMUNICATION SYSTEMS, LECTURE NOTES IN COMPUTER SCIENCE
, 1995
"... This article describes a new version of the QPNTool now supporting specification and analysis of hierarchically combined Queueing Petri nets (HQPNs). HQPNs are an extension of QPNs allowing the refinement of places by QPN subnets and/or queues. HQPNs can be analysed with respect to qualitative ..."
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Cited by 26 (4 self)
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This article describes a new version of the QPNTool now supporting specification and analysis of hierarchically combined Queueing Petri nets (HQPNs). HQPNs are an extension of QPNs allowing the refinement of places by QPN subnets and/or queues. HQPNs can be analysed with respect to qualitative and quantitative aspects. Quantitative analysis is based on numerical Markov chain analysis. In contrast to conventional techniques the Markov chain underlying a HQPN is analysed by an approach exploiting the hierarchical structure of the model which results in a tensor representation of the generator matrix. This technique extends the size of solvable state spaces by one order of magnitude. Qualitative analysis of HQPNs relies on efficient analysis techniques based on Petri net theory. The new version of QPNTool implements the above analysis approaches supported by a graphical interface for a convenient specification of complex models.