This book constitutes the refereed proceedings of the 20th International Conference on Application and Theory of Petri Nets, ICATPN'99, held in Williamsburg, Virginia, USA, in June 1999. The 21 revised full papers presented were carefully selected from 45 submissions. Also included are three invited presentations. The book presents state-of-the-art research results on all current aspects of Petri nets as well as advanced applications in a variety of areas.

This volume contains the proceedings of the 26th International Conference on Application and Theory of Petri Nets and Other Models of Concurrency (ICATPN 2005). The Petri net conferences serve to discuss yearly progress in the ?eld of Petri nets and related models of concurrency, and to foster new - vancesintheapplicationandtheoryofPetrinets.Theconferencestypicallyhave 100–150 participants, one third from industry and the others from universities and research institutions, and they always take place in the last week of June. SuccessiveeditionsoftheconferencearecoordinatedbytheSteeringCommittee, whose members are listed on the next page, which also supervises several other activities—see the Petri Nets World at the URLwww.daimi.au.dk/PetriNets. The 2005 conference was organized in Miami by the School of Computer Science at Florida International University (USA). We would like to express our deep thanks to the Organizing Committee, chaired by Xudong He, for the time and e?ort invested to the bene?t of the community in making the event successful. Several tutorials and workshops were organized within the conf- ence, covering introductory and advanced aspects related to Petri nets. Detailed information can be found at the conference URLwww.cs.fiu.edu/atpn2005. We received altogether 71 submissions from authors in 22 countries. Two submissions were not in the scope of the conference. The Program Comm- tee selected 23 contributions from the remaining 69 submissions, classi?ed into three categories: application papers (6 accepted, 25 submitted), theory papers (14 accepted, 40 submitted), and tool presentations (3 accepted, 4 submitted).

The refereed proceedings of the 24th International Conference on Applications and Theory of Petri Nets, ICATPN 2003, held in Eindhoven, The Netherlands, in June 2003. The 25 revised full papers presented together with 6 invited contributions were carefully reviewed and selected from 77 submissions. All current issues on research and development in the area of Petri nets are addressed, in particular concurrent systems design and analysis, model checking, networking, business process modeling, formal methods in software engineering, agent systems, systems specification, systems validation, discrete event systems, protocols, and prototyping.

Concurrency and distribution have become the dominant paradigm and concern in computer science. Despite the fact that much of the early research in object-oriented programming focused on sequential systems, objects are a natural unit of distribution and concurrency - as elucidated early on by research on the Actor model. Thus, models and theories of concurrency, the oldest one being Petri nets, and their relation to objects are an attractive topic of study. This book presents state-of-the-art results on Petri nets and concurrent object-oriented programming in a coherent and competent way. The 24 thoroughly reviewed and revised papers are organized in three sections. The first consists of long papers, each presenting a detailed approach to integrating Petri nets and object-orientation. Section II includes shorter papers with emphasis on concrete examples to demonstrate the approach. Finally, section III is devoted to papers which significantly build on the Actor model of computation.

Traditionally, models and methods for the analysis of the functional correctness of reactive systems, and those for the analysis of their performance (and - pendability) aspects, have been studied by di?erent research communities. This has resulted in the development of successful, but distinct and largely unrelated modeling and analysis techniques for both domains. In many modern systems, however, the di?erence between their functional features and their performance properties has become blurred, as relevant functionalities become inextricably linked to performance aspects, e.g. isochronous data transfer for live video tra- mission. During the last decade, this trend has motivated an increased interest in c- bining insights and results from the ?eld of formal methods – traditionally - cused on functionality – with techniques for performance modeling and analysis. Prominent examples of this cross-fertilization are extensions of process algebra and Petri nets that allow for the automatic generation of performance models, the use of formal proof techniques to assess the correctness of randomized - gorithms, and extensions of model checking techniques to analyze performance requirements automatically. We believe that these developments markthe - ginning of a new paradigm for the modeling and analysis of systems in which qualitative and quantitative aspects are studied from an integrated perspective. We are convinced that the further worktowards the realization of this goal will be a growing source of inspiration and progress for both communities.

\My tailor is Object-Oriented". Most software systems that have been built - cently are claimed to be Object-Oriented. Even older software systems that are still in commercial use have been upgraded with some OO ?avors. The range of areas where OO can be viewed as a \must-have" feature seems to be as large as the number of elds in computer science. If we stick to one of the original views of OO, that is, to create cost-e ective software solutions through modeling ph- ical abstractions, the application of OO to any eld of computer science does indeed make sense. There are OO programming languages, OO operating s- tems, OO databases, OO speci cations, OO methodologies, etc. So what does a conference on Object-Oriented Programming really mean? I honestly don’t know. What I do know is that, since its creation in 1987, ECOOP has been attracting a large number of contributions, and ECOOP conferences have ended up with high-quality technical programs, featuring interesting mixtures of theory and practice. Among the 183 initial submissions to ECOOP’99, 20 papers were selected for inclusion in the technical program of the conference. Every paper was reviewed by three to ve referees. The selection of papers was carried out during a t- day program committee meeting at the Swiss Federal Institute of Technology in Lausanne. Papers were judged according to their originality, presentation qu- ity, and relevance to the conference topics.

Since their introduction nearly 40 years ago, research on Petri nets has diverged in many different directions. Various classes of Petri net, motivated either by theory or applications, with its own specific features and methods of analysis, have been proposed and studies in depth. These successful developments have led to a very heterogeneous landscape of diverse models, and this, in turn, has stimulated research on concepts and approaches that contribute to unifying and structuring the diverse landscape. This state-of-the-art survey presents the most relevant approaches to unifying Petri nets in a systematic and coherent way. The 14 chapters written by leading researchers are organized in topical sections on application-oriented approaches, unifying frameworks, and theoretical approaches.

This book constitutes the refereed proceedings of the 30th International Conference on Applications and Theory of Petri Nets and Other Models of Concurrency, PETRI NETS 2009, held in Paris, France, in June 2009. The 19 revised papers classified as theory papers (13), application papers (1), and tool papers (5) were carefully reviewed and selected from 46 submissions. All current issues on research and development in the area of Petri nets and related models of concurrent systems are addressed, novel tools as well as substantial enhancements to existing tools are presented.

A Petri net is a mathematical representation of a network. This book first introduces the basic models including time and stochastic extensions, in particular place-transition and high level Petri nets. Their modeling and design capabilities are illustrated by a set of representations of interest in operating and communication systems. The volume then addresses the related verification problems and proposes corresponding solutions by introducing the main notions needed to fully understand the behavior and properties behind Petri nets. Particular attention is devoted to how systems can be fully represented and analyzed in terms of their behavioral, time, and stochastic aspects by using the same formal approach and semantic basis. Finally, illustrative examples are presented in the important fields of interoperability in telecommunication services, programming languages, multimedia architectures, manufacturing systems, and communication protocols.